Search tips
Search criteria

Results 1-25 (43)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
1.  Engaging with community-based public and private mid-level providers for promoting the use of modern contraceptive methods in rural Pakistan: results from two innovative birth spacing interventions 
Reproductive Health  2016;13:25.
Family planning (FP) interventions aimed at reducing population growth have negligible during the last two decades in Pakistan. Innovative FP interventions that help reduce the growing population burden are the need of the hour. Marie Stopes Society - Pakistan implemented an operational research project - ‘Evidence for Innovating to Save Lives’, to explore effective and viable intervention models that can promote healthy timing and spacing of pregnancy in rural and under-served communities of Sindh, Punjab and Khyber Pakhtunkhwa provinces of Pakistan.
We conducted a quasi-experimental (pre - and post-intervention with control arm) study to assess the effectiveness of each of the two intervention models, 1) Suraj model (meaning ‘Sun’ in English), which uses social franchises (SF) along with a demand-side financing (DSF) approach using free vouchers, and 2) Community Midwife (CMW) model, in promoting the use of modern contraceptive methods compared to respective controls.
Baseline and endline cross-sectional household surveys were conducted, 24 months apart, by recruiting 5566 and 6316 married women of reproductive age (MWRA) respectively. We used Stata® version 8 to report the net effect of interventions on outcome indicators using difference-in-differences analysis. Multivariate Cox proportional hazard regression analysis was used to assess the net effect of the intervention on current contraceptive use, keeping time constant and adjusting for other variables in the model.
The Suraj model was effective in significantly increasing awareness about FP methods among MWRA by 14 % percentage points, current contraceptive use by 5 % percentage points and long term modern method - intrauterine device (IUD) use by 6 % percentage points. The CMW model significantly increased contraceptive awareness by 28 % percentage points, ever use of contraceptives by 7 % percentage points and, IUD use by 3 % percentage points. Additionally the Suraj intervention led to a 35 % greater prevalence (prevalence ratio: 1.35, 95 % CI: 1.22–1.50) of contraceptive use among MWRA.
Suraj intervention highlights the importance of embedding subsidized FP services within the communities of the beneficiaries. The outcomes of the CMW intervention also improved the use of long-term contraceptives. These findings indicate the necessity of designing and implementing FP initiatives involving local mid-level providers to expand contraceptive coverage in under-served areas.
PMCID: PMC4797360  PMID: 26987368
Family planning; Birth spacing; Contraception; Vouchers; Community midwives; Suraj; Rural Pakistan
2.  Dynamics of CYP51: implications for function and inhibitor design 
Sterol 14α-demethylase (cytochrome P450 family 51 (CYP51)) is an essential enzyme occurring in all biological kingdoms. In eukaryotes, it is located in the membrane of the endoplasmic reticulum. Selective inhibitors of trypanosomal CYP51s that do not affect the human CYP51 have been discovered in vitro and found to cure acute and chronic mouse Chagas disease without severe side effects in vivo. Crystal structures indicate that CYP51 may be more rigid than most CYPs, and it has been proposed that this property may facilitate antiparasitic drug design. Therefore, to investigate the dynamics of trypanosomal CYP51, we built a model of membrane-bound Trypanosoma brucei CYP51 and then performed molecular dynamics simulations of T. brucei CYP51 in membrane-bound and soluble forms. We compared the dynamics of T. brucei CYP51 with those of human CYP51, CYP2C9, and CYP2E1. In the simulations, the CYP51s display low mobility in the buried active site although overall mobility is similar in all the CYPs studied. The simulations suggest that in CYP51, pathway 2f serves as the major ligand access tunnel, and both pathways 2f (leading to membrane) and S (leading to solvent) can serve as ligand egress tunnels. Compared with the other CYPs, the residues at the entrance of the ligand access tunnels in CYP51 have higher mobility that may be necessary to facilitate the passage of its large sterol ligands. The water (W) tunnel is accessible to solvent during most of the simulations of CYP51, but its width is affected by the conformations of the heme's two propionate groups. These differ from those observed in the other CYPs studied because of differences in their hydrogen-bonding network. Our simulations give insights into the dynamics of CYP51 that complement the available experimental data and have implications for drug design against CYP51 enzymes.
PMCID: PMC4337246  PMID: 25601796
sterol 14α-demethylase; CYP51; cytochrome P450; molecular dynamics simulation; membrane-bound protein; protein dynamics; ligand tunnel; heme propionate groups
3.  Parental beliefs and practice of spiritual methods for their sick children at a tertiary care hospital of Pakistan- a cross sectional questionnaire study 
Complementary and alternative medicine (CAM) comprises a variety of health care systems, practices, and products that are not usually thought to be part of allopathic medicine. This study investigated the parental beliefs and practices for use of spiritual methods in the treatment and early recovery of their children.
We performed a cross-sectional, descriptive study with convenience sampling of parents/caregivers of sick children who were admitted to the Children’s Hospital in Multan. A trained interviewer collected the data.
A total of 1280 forms were analyzed. The majority of respondents were mothers (1053, 82.4 %), they resided in Multan (817, 63.8 %), and were not educated (754, 58.9 %). A total of 420 (32.8 %) respondents had a low socioeconomic background, 601 (47 %) were middle class, and 259 (20.2 %) were upper class. Grandmothers/mothers advised spiritual methods in the majority of respondents (605, 85.9 %). The parents used a variety of spiritual methods in 704 (55 %) children. Economic status and education showed an inverse relation with the use of CAM. A total of 809 (63.2 %) respondents believed that only a drug would heal the disease, while 575 (44.9 %) believed that spiritual methods have a 25 %–50 % role in healing. A total of 1269 (99.1 %) respondents believed that allopathic drugs are needed for healing, while only 0.9 % considered otherwise.
The majority of people believe that CAM is a contributory factor towards healing and does not interfere with allopathic treatment.
Electronic supplementary material
The online version of this article (doi:10.1186/s12906-016-0986-3) contains supplementary material, which is available to authorized users.
PMCID: PMC4710972  PMID: 26758383
Complementary and alternative medicine; Knowledge; Attitude and practice; Spiritual; Taveez; Beliefs; Children
4.  Determinants of Method Switching among Social Franchise Clients Who Discontinued the Use of Intrauterine Contraceptive Device 
Introduction. Women who do not switch to alternate methods after contraceptive discontinuation, for reasons other than the desire to get pregnant or not needing it, are at obvious risk for unplanned pregnancies or unwanted births. This paper examines the factors that influence women to switch from Intrauterine Contraceptive Device (IUCD) to other methods instead of terminating contraceptive usage altogether. Methods. The data used for this study comes from a larger cross-sectional survey conducted in nine (9) randomly selected districts of Sindh and Punjab provinces of Pakistan, during January 2011. Using Stata 11.2, we analyzed data on 333 women, who reported the removal of IUCDs due to reasons other than the desire to get pregnant. Results. We found that 39.9% of the women do not switch to another method of contraception within one month after IUCD discontinuation. Use of contraception before IUCD insertion increases the odds for method switching by 2.26 times after removal. Similarly, postremoval follow-up by community health worker doubles (OR = 2.0) the chances of method switching. Compared with women who received free IUCD service (via voucher scheme), the method switching is 2.01 times higher among women who had paid for IUCD insertion. Conclusion. To increase the likelihood of method switching among IUCD discontinuers this study emphasizes the need for postremoval client counseling, follow-up by healthcare provider, improved choices to a wider range of contraceptives for poor clients, and user satisfaction.
PMCID: PMC4630392  PMID: 26576454
5.  Family Planning Knowledge, Attitudes, and Practices among Married Men and Women in Rural Areas of Pakistan: Findings from a Qualitative Need Assessment Study 
This paper presents the findings of a qualitative assessment aimed at exploring knowledge, attitudes, and practices regarding family planning and factors that influence the need for and use of modern contraceptives. A descriptive exploratory study was conducted with married women and men aged between 15 and 40. Overall, 24 focus group discussions were conducted with male and female participants in three provinces of Pakistan. The findings reveal that the majority knew about some modern contraceptive methods, but the overall contraceptive use was very low. Knowledge and use of any contraceptive method were particularly low. Reasons for not using family planning and modern contraception included incomplete family size, negative perceptions, in-laws' disapproval, religious concerns, side-effects, and lack of access to quality services. The majority preferred private facilities over the government health facilities as the later were cited as derided. The study concluded the need for qualified female healthcare providers, especially for long term family planning services at health facilities instead of camps arranged occasionally. Addressing issues around access, affordability, availability, and sociocultural barriers about modern contraception as well as involving men will help to meet the needs and ensure that the women and couples fulfill their childbearing and reproductive health goals.
PMCID: PMC4569791  PMID: 26421316
6.  Assessing predictors of contraceptive use and demand for family planning services in underserved areas of Punjab province in Pakistan: results of a cross-sectional baseline survey 
Reproductive Health  2015;12:25.
Although Pakistan was one of the first countries in Asia to launch national family planning programs, current modern contraceptive use stands at only 26% with a method mix skewed toward short-acting and permanent methods. As part of a multiyear operational research study, a baseline survey was conducted to understand the predictors of contraceptive use and demand for family planning services in underserved areas of Punjab province in Pakistan. This paper presents the baseline survey results; the outcomes of the intervention will be presented in a separate paper after the study has been completed.
A cross-sectional baseline household survey was conducted with randomly selected 3,998 married women of reproductive age (MWRA) in the Chakwal, Mianwali, and Bhakkar districts of Punjab. The data were analyzed on SPSS 17.0 using simple descriptive and logistic regression.
Most of the women had low socio-economic status and were younger than 30 years of age. Four-fifths of the women consulted private sector health facilities for reproductive health services; proximity, availability of services, and good reputation of the provider were the main predicators for choosing the facilities. Husbands were reported as the key decision maker regarding health-seeking and family planning uptake. Overall, the current contraceptive use ranged from 17% to 21% across the districts: condoms and female sterilization were widely used methods. Woman’s age, husband’s education, wealth quintiles, spousal communication, location of last delivery, and favorable attitude toward contraception have an association with current contraceptive use. Unmet need for contraception was 40.6%, 36.6%, and 31.9% in Chakwal, Mianwali, and Bhakkar, respectively. Notably, more than one fifth of the women across the districts expressed willingness to use quality, affordable long-term family planning services in the future.
The baseline results highlight the need for quality, affordable long-term family planning services close to women’s homes. Furthermore, targeted community mobilization and behavior change efforts can lead to increased awareness, acceptability, and use of family planning and birth spacing services.
PMCID: PMC4383051  PMID: 25880987
7.  Comparing effectiveness of two client follow-up approaches in sustaining the use of Long Acting Reversible Contraceptives (LARC) among the underserved in rural Punjab, Pakistan: a study protocol and participants’ profile 
Reproductive Health  2015;12:9.
Pakistan observes a very high i.e. 37 percent modern contraceptive method related discontinuation rates within 12 months of their initiation. And almost 10 percent of these episodes of discontinuation happened due to the side effects or health concerns experienced by the women. Most importantly, it was noted that more than 12,000 first-level care facilities are located in the rural areas, including rural health centers, basic health units, and family welfare centers, but more than 30% of these facilities are nonfunctional. This paper presents a study protocol and participants’ profiling of a prospective cohort follow-up to compare the effectiveness of household based and telephonic approaches in sustaining the use of Long Acting Reversible Contraceptives (LARC) whilst to facilitate lowering method related discontinuation and increasing switching amongst the contraceptive users.
A 12-month multi-centre, non-inferiority prospective user follow-up is employed using three different study categories: a) household based follow-up; b) telephonic follow-up; and c) passive or need-based follow-up along with the hypothetical assumption that the telephonic client follow-up is not inferior to the household based follow-up by continuation rate of LARC and the telephonic follow-up is less-costly than the household based client follow-up. This follow-up will be conducted in 22 health facilities – (16 rural and 6 urban based facilities) in district Chakwal. The first two study categories will receive scheduled but different follow-up from the field workers at 1, 3, 6, 9, and 12 month while the third one i.e. the ‘passive or need-based follow-up’ will serve as a control group. Using sampling software PASS 11, it was estimated to have 414 clients in each study category and around 1366 clients will be recruited to account for 10% attrition rate.
The study will help us to examine a more convenient method of effective follow-up for managing side effects, decreasing method discontinuation and increasing switching amongst users. The study information will also facilitate to develop a robust, effective and efficient mechanism for client follow-up to promote the continuation rates of LARC methods. The follow-up results and lessons learnt will be widely shared with stakeholders for their implementation and streamlining in health system.
PMCID: PMC4429346  PMID: 25971781
Family planning; Long acting reversible contraceptives; Method discontinuation; Non-inferiority prospective client follow-up; Maternal health; Study protocol; Punjab; Pakistan
9.  Crystal structure of 1-benzoyl-3-(4-fluoro­phen­yl)thio­urea 
The title compound, C14H11FN2OS, contains two mol­ecules (A and B) in the asymmetric unit, with different conformations. In mol­ecule A, the dihedral angles between the central thio­urea grouping and the phenyl and fluoro­benzene rings are 28.77 (8) and 41.82 (8)°, respectively, and the dihedral angle between the ring planes is 70.02 (9)°. Equivalent data for mol­ecule B are 8.46 (8), 47.78 (8) and 52.99 (9)°, respectively. Both mol­ecules feature an intra­molecular N—H⋯O hydrogen bond, which closes an S(6) ring. In the crystal, A+B dimers linked by pairs of N—H⋯S hydrogen bonds generate R 2 2(8) loops.
PMCID: PMC4186107  PMID: 25309204
crystal structure; thio­urea; amide; hydrogen-bonded dimers
10.  A study protocol: using demand-side financing to meet the birth spacing needs of the underserved in Punjab Province in Pakistan 
Reproductive Health  2014;11:39.
High fertility rates, unwanted pregnancies, low modern contraceptive prevalence and a huge unmet need for contraception adversely affect women’s health in Pakistan and this problem is compounded by limited access to reliable information and quality services regarding birth spacing especially in rural and underserved areas. This paper presents a study protocol that describes an evaluation of a demand-side financing (DSF) voucher approach which aims to increase the uptake of modern contraception among women of the lowest two wealth quintiles in Punjab Province, Pakistan.
This study will use quasi-experimental design with control arm and be implemented in: six government clinics from the Population Welfare Department; 24 social franchise facilities branded as ‘Suraj’ (Sun), led by Marie Stopes Society (a local non-governmental organization); and 12 private sector clinics in Chakwal, Mianwali and Bhakkar districts. The study respondents will be interviewed at baseline and endline subject to voluntary acceptance and medical eligibility. In addition, health service data will record each client visit during the study period.
The study will examine the impact of vouchers in terms of increasing the uptake of modern contraception by engaging private and public sector service providers (mid-level and medical doctors). If found effective, this approach can be a viable solution to satisfying the current demand and meeting the unmet need for contraception, particularly among the poorest socio-economic group.
PMCID: PMC4059733  PMID: 24885657
Demand-side financing; Voucher; Social franchising; Quasi-experimental; Maternal health; Unmet need for modern contraception; Birth spacing; Study protocol; Punjab; Pakistan
11.  Rationale, design, and cohort enrolment of a prospective observational study of the clinical performance of the new contraceptive implant (Femplant) in Pakistan 
The use of hormonal implants has gained positive traction in family planning programs in recent times. Compared to other popular methods, such as long-term reversible intrauterine devices, the use of hormonal implants as a family planning method has distinct advantages in terms of long-term efficiency and better user compliance and availability. This paper presents a study protocol to document and evaluate the efficacy, safety, and acceptability of Femplant (contraceptive implant) in Pakistan during the first year of its use among married women of reproductive age (18–44 years) at clinics in two provinces of Pakistan (Sindh and Punjab).
Materials and methods
A total of 724 married women were enrolled in a noncomparative prospective observational study. The study involved six government clinics from the Population Welfare Department in Sindh Province and 13 clinics run by the Marie Stopes Society (a local nongovernmental organization) in both provinces. The participation of women was subject to voluntary acceptance and medical eligibility. All respondents were interviewed at baseline and subsequently at each scheduled visit during the study period. Side effects, complications and adverse events, if any, were recorded for every participant at each visit to the facility.
Over the next 5-year period (2013–2018), 27 million hormonal implants will be made available in lower- to middle-income countries by international donors and agencies. The evidence generated from this study will identify factors affecting the acceptability and satisfaction of end users with Femplant (Sino-implant II). This will help to guide policies to enhance access to and the use of long-acting contraceptive implants in Pakistan and similar developing countries.
PMCID: PMC4045175  PMID: 24920939
safety; efficacy; acceptability; implant; Femplant; contraception; family planning; Pakistan
14.  Comparative sequence analysis of citrate synthase and 18S ribosomal DNA from a wild and mutant strains of Aspergillus niger with various fungi 
Bioinformation  2014;10(1):1-7.
A mutation was induced in Aspergillus niger wild strain using ethidium bromide resulting in enhanced expression of citric acid by three folds and 112.42 mg/mL citric acid was produced under optimum conditions with 121.84 mg/mL of sugar utilization. Dendograms of 18S rDNA and citrate synthase from different fungi including sample strains were made to assess homology among different fungi and to study the correlation of citrate synthase gene with evolution of fungi. Subsequent comparative sequence analysis revealed strangeness between the citrate synthase and 18S rDNA phylogenetic trees. Furthermore, the citrate synthase movement suggests that the use of traditional marker molecule of 18S rDNA gives misleading information about the evolution of citrate synthase in different fungi as it has shown that citrate synthase gene transferred independently among different fungi having no evolutionary relationships. Random amplified polymorphic DNA (RAPD-PCR) analysis was also employed to study genetic variation between wild and mutant strains of A. niger and only 71.43% similarity was found between both the genomes. Keeping in view the importance of citric acid as a necessary constituent of various food preparations, synthetic biodegradable detergents and pharmaceuticals the enhanced production of citric acid by mutant derivative might provide significant boost in commercial scale viability of this useful product.
CS - Citrate synthase, CA - Citric acid, RAPD - Random amplified polymorphic DNA, TAF - Total amplified fragments, PAF - Polymorphic amplified fragments, CAF - Common amplified fragments.
PMCID: PMC3916811  PMID: 24516318
citrate synthase; Aspergillus niger; phylogenetic analysis; polymorphism; RAPD-PCR
15.  Impact of Social Franchising on Contraceptive Use When Complemented by Vouchers: A Quasi-Experimental Study in Rural Pakistan 
PLoS ONE  2013;8(9):e74260.
Pakistan has had a low contraceptive prevalence rate for the last two decades; with preference for natural birth spacing methods and condoms. Family planning services offered by the public sector have never fulfilled the demand for contraception, particularly in rural areas. In the private sector, cost is a major constraint. In 2008, Marie Stopes Society – a local NGO started a social franchise programme along with a free voucher scheme to promote uptake of IUCDs amongst the poor. This paper evaluates the effectiveness of this approach, which is designed to increase modern long term contraceptive awareness and use in rural areas of Pakistan.
We used a quasi-experimental study design with controls, selecting one intervention district and one control district from the Sindh and Punjab provinces. In each district, we chose a total of four service providers. A baseline survey was carried out among 4,992 married women of reproductive age (MWRA) in February 2009. Eighteen months after the start of intervention, an independent endline survey was conducted among 4,003 women. We used multilevel logistic regression for analysis using Stata 11.
Social franchising used alongside free vouchers for long term contraceptive choices significantly increased the awareness of modern contraception. Awareness increased by 5% in the intervention district. Similarly, the ever use of modern contraceptive increased by 28.5%, and the overall contraceptive prevalence rate increased by 19.6%. A significant change (11.1%) was recorded in the uptake of IUCDs, which were being promoted with vouchers.
Family planning franchise model promotes awareness and uptake of contraceptives. Moreover, supplemented with vouchers, it may enhance the use of IUCDs, which have a significant cost attached. Our research also supports a multi-pronged approach- generating demand through counselling, overcoming financial constraints by offering vouchers, training, accreditation and branding of the service providers, and ensuring uninterrupted contraceptive supplies.
PMCID: PMC3772094  PMID: 24069287
16.  5-Acetyl-3-(5-phenyl-1H-pyrazol-3-yl)-1,3,4-thia­diazol-2(3H)-one monohydrate 
In the title hydrate, C13H10N4O2S·H2O, the dihedral angles between the central pyrazole ring and its pendant phenyl and thia­diazole rings are 9.93 (8) and 4.56 (7)°, respectively. In the crystal, the components are linked by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, generating [100] chains incorporating R 4 4(10) loops. A weak C—H⋯O inter­action helps to consolidate the packing.
PMCID: PMC3648319  PMID: 23723939
17.  Prevalence of obstructive sleep apnea in surgical patients presenting to a tertiary care teaching hospital in India: A preliminary study 
Saudi Journal of Anaesthesia  2013;7(2):155-159.
Obstructive sleep apnea (OSA) is often not diagnosed in patients presenting for surgical procedures thereby increasing the incidence of adverse perioperative course. Early diagnosis of this disease is important in modifying anesthetic management as well as utilizing specific means which may decrease the complications and improve the patient outcome.
Patients greater than eighteen years of age, ASA I-III scheduled for elective surgical procedures under anesthesia were randomly selected. Their demographic data, diagnosis and nature of surgery were noted in a semi-structured performa. They were then screened for the presence of OSA with the help of a STOP BANG questionnaire.
This study included two hundred four patients randomly selected. Slight female predominance was seen in this sample (55.4%). Mean age of the subjects was 42.7 years (SD=15.08). 24.5% subjects were at high risk for OSA (STOP-BANG>3) with a male predominance (72% versus 37% in low risk group; X2=18.62; P<0.001). High risk OSA subjects had higher prevalence of cardiovascular risk factors (57% vs. 11.7% in low risk group; X2=33.35; P<0.001). Similarly, this group had a higher prevalence of asthma and chronic obstructive pulmonary disease (COPD) (14% versus 3.8% in low risk group; X2=6.54; P=0.03). Prevalence of diabetes mellitus (22%) and hypothyroidism (6%) was also higher in this group (5.2% and 1.9% in low risk group respectively; X2=15.42; P<0.001).
High degree of suspicion and knowledge of association of OSA and medical diseases may help in detection of such cases and decrease the rate of perioperative complications thus improving patients safety.
PMCID: PMC3737691  PMID: 23956715
Anaesthesia; complication; obstructive sleep apnea; STOP BANG
18.  IUD discontinuation rates, switching behavior, and user satisfaction: findings from a retrospective analysis of a mobile outreach service program in Pakistan 
In Pakistan, the uptake rate for the intrauterine device (IUD) is very low at 2.5%. The most popular modern contraceptive methods in Pakistan are female sterilization and use of condoms. The Marie Stopes Society established its mobile outreach service delivery program with the aim of increasing use of modern quality contraceptive services, including the long-term reversible IUD, by women living in hard-to-reach areas. The present study attempts to assess IUD discontinuation rates and associated factors, including switching behavior and level of satisfaction with this type of service delivery.
Using a cross-sectional approach, we contacted 681 women who had received an IUD from the Marie Stopes Society mobile outreach program during July and August 2009. Successful interviews were conducted with 639 of these women using a structured questionnaire. The data were analyzed with Stata 11.2 using simple descriptive Chi-square and Cox proportional techniques.
Analysis revealed that 19.4% (95% confidence interval 16.3–22.5) of the women discontinued use of their IUD at 10 months and, of these women, the majority (69.4%) cited side effects as the main reason for discontinuation. Other factors, such as geographical catchment province, age of the woman, history of contraceptive use before IUD insertion, and side effects following insertion of the device, were found to be significantly associated with IUD. Amongst the women who had their IUD removed, 56.5% did not switch to any other contraceptive method, while 36.3% switched to either short-term or traditional methods, such as withdrawal, rhythm, and folk methods. Degree of satisfaction with the device was also significantly associated with discontinuation.
Early discontinuation and not switching to another contraceptive method increases the risk of unplanned pregnancy. Health care workers should be trained in managing clients’ concerns about the IUD to prevent discontinuation and providing counseling services for clients to select an alternative contraceptive method if they decide to discontinue.
PMCID: PMC3555552  PMID: 23359788
intrauterine device; mobile outreach services; discontinuation; Pakistan
19.  2-[(2-Hy­droxy­naphthalen-1-yl)methyl­idene­amino]-5,6,7,8-tetra­hydro-4H-cyclo­hepta­[b]thio­phene-3-carbonitrile 
Two independent mol­ecules, A and B, comprise the asymmetric unit of the title compound, C21H18N2OS, with the difference in the angle of orientation between the naphthalene ring system and the mean plane of the cyclo­heptyl ring [16.13 (1) in A and 11.48 (5)° in B], being evident. The cyclo­heptyl ring adopts a distorted chair conformation in each mol­ecule with r.m.s. deviations of 0.2345 (4) (A) and 0.2302 (4) Å (B). Intra­molecular O—H⋯N hydrogen bonding generates planar six-membered S(6) loops with r.m.s. deviations of 0.0099 (1) (A) and 0.0286 (1) Å (B).
PMCID: PMC3569254  PMID: 23424477
20.  Nanostructured materials with biomimetic recognition abilities for chemical sensing 
Nanoscale Research Letters  2012;7(1):328.
Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly imprinted sensor layers lead to selectivity factors of at least 2 compared to other bivalent ions. In the same way, H-bonds can be utilized for such sensing purposes, as shown in the case of Escherichia coli. The respective molecularly imprinted polymer leads to the selectivity factor of more than 5 between the W and B strains, respectively. Furthermore, nanoparticles with optimized Pearson hardness allow for designing sensors to detect organic thiols in air. The ‘harder’ MoS2 yields only about 40% of the signals towards octane thiol as compared to the ‘softer’ Cu2S. However, both materials strongly prefer molecules with -SH functionality over others, such as hydrocarbon chains. Finally, selectivity studies with wheat germ agglutinin (WGA) reveal that artificial receptors yield selectivities between WGA and bovine serum albumin that are only about a factor of 2 which is smaller than natural ligands.
PMCID: PMC3434081  PMID: 22721566
Bivalent copper ions; Organic vapors; Wheat germ agglutinin lectin; Escherichia coli; Quartz crystal microbalance
21.  A Case of Fetus in Fetu 
Fetus in fetu is a rare developmental aberration, characterized by encasement of partially developed monozygotic, diamniotic, and monochorionic fetus into the normally developing host. A 4-month-old boy presented with abdominal mass. Radiological investigations gave the suspicion of fetus in fetu. At surgery a fetus enclosed in an amnion like membrane at upper retroperitoneal location was found and excised. The patient is doing well after the operation.
PMCID: PMC3418045  PMID: 22953303
Fetus in fetu;  Teratoma;  Abdominal mass
22.  Butyl 4-(4-methyl­benzene­sulfonamido)­benzoate 
In the title compound, C18H21NO4S, the aromatic rings are almost normal to each other, with a dihedral angle of 89.27 (18)°. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O inter­action, which generates an S(6) motif. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds lead to the formation of chains propagating along [010]. Neighbouring chains are linked via a C—H⋯π inter­action. The –CH2CH2CH3 atoms of the butyl group are disordered over two sets of sites, with a refined site-occupancy ratio of 0.536 (16):0.464 (16).
PMCID: PMC3344642  PMID: 22590404
23.  Methyl 5-bromo-2-hy­droxy­benzoate 
The title compound, C8H7BrO3, is almost planar (r.m.s. deviation for the non-H atoms = 0.055 Å). In the crystal, O—H⋯O hydrogen bonds link the mol­ecules into C(6) chains propagating in [010]. Very weak aromatic π–π inter­actions [centroid–centroid distances = 3.984 (5) and 3.982 (5) Å] also occur.
PMCID: PMC3344579  PMID: 22590341
24.  Cyano­methyl 4-(4-methyl­benzene­sulfonamido)­benzoate 
The title mol­ecule, C16H14N2O4S, adopts an L-shaped conformation, with the central C—S—N—C torsion angle being −69.1 (3)°. The two benzene rings form a dihedral angle of 89.94 (15)°. The mol­ecular conformation may be influenced by a weak intra­molecular C—H⋯O hydrogen bond which generates an S(6) ring motif. In the crystal, mol­ecules are linked by N—H⋯O and weak C—H⋯O hydrogen bonds, forming chains propagating along the b axis. Weak C—H⋯N hydrogen bonds connect the chains into a two-dimensional network parallel to (011). The crystal studied was an inversion twin, the ratio of components being 0.7 (1):0.3 (1).
PMCID: PMC3344598  PMID: 22590360
25.  Propyl 2-(4-methyl­benzene­sulfonamido)­benzoate 
In the title compound, C17H19NO4S, the terminal ethyl group is disordered over two sets of sites, with refined site occupancies of 0.536 (7) and 0.464 (7). The dihedral angle between the two aromatic rings is 81.92 (12)°. The mol­ecular conformation is stabilized by intra­molecular N—H⋯O and C—H⋯O hydrogen bonds, which generate S(6) motifs. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains along the b axis.
PMCID: PMC3344515  PMID: 22590277

Results 1-25 (43)