The enterocin biosynthesis gene cluster represents the most versatile type II PKS system investigated to date. A large series of divergent metabolites are naturally generated from the single biochemical pathway, which has several metabolic options for creating structural diversity. The absence of cyclase and aromatase gene products and the involvement of an oxygenase-catalyzed Favorskii-like rearrangement provide insight into the observed spontaneity of this pathway. This system provides the foundation for engineering hybrid expression sets in the generation of structurally novel compounds for use in drug discovery.

BackgroundBangladesh is a highly populous country with three-quarters rural population. Pressing national shortages in health professionals has resulted in high vacancy rates in rural areas. These are compounded by excessive absenteeism and low retention among nurses and doctors posted to rural locations. This study attempts to ascertain reasons for providers’ reluctance to work in rural and remote areas and to identify ways in which these barriers to appropriate staffing might be resolved.MethodsThis is a qualitative study based on in-depth interviews with healthcare providers (n = 15) and facility managers (n = 4) posted in rural areas, and key informant interviews with health policymakers at the national level (n = 2). Interview guides were written in English and translated and administered in Bengali. The collected data were re-translated and analyzed in English. Braun and Clarke’s thematic analysis approach (data familiarization, coding, identifying and reviewing themes, and producing a final report) was used.ResultsParticipants reported poor living conditions in rural areas (e.g., poor housing facilities and unsafe drinking water); overwhelming workloads with poor safety and insufficient equipment; and a lack of opportunities for career development, and skill enhancement. They reported insufficient wages and inadequate opportunities for private practice in rural areas. Managers described their lack of sufficient authority to undertake disciplinary measures for absenteeism. They also pointed at the lack of fairness in promotion practices of the providers. Policymakers acknowledged unavailability or insufficient allowances for rural postings. There is also a lack of national policy on rural retention.ConclusionsThe findings revealed a complex interplay of factors influencing doctors’ and nurses’ availability in rural and remote public health facilities from the perspective of different players in the healthcare delivery system of Bangladesh. In addition, the study generated several possibilities for improvement, including increased allowances and incentives for rural posting; a transparent and fair promotion system for serving in rural areas; enhanced authority of the local managers for reducing worker absenteeism; and improved national policies on rural retention.

The menstrual cycle is characterized by predictable patterns of physiological change across timescales. Although patterns of reproductive hormones across the menstrual cycle, particularly ultradian rhythms, are well described, monitoring these measures repeatedly to predict the preovulatory luteinizing hormone (LH) surge is not practical. In the present study, we explored whether non-invasive measures coupled to the reproductive system: high frequency distal body temperature (DBT), sleeping heart rate (HR), sleeping heart rate variability (HRV), and sleep timing, could be used to anticipate the preovulatory LH surge in women. To test this possibility, we used signal processing to examine these measures in 45 premenopausal and 10 perimenopausal cycles alongside dates of supra-surge threshold LH and menstruation. Additionally, urinary estradiol and progesterone metabolites were measured daily surrounding the LH surge in 20 cycles. Wavelet analysis revealed a consistent pattern of DBT and HRV ultradian rhythm (2–5 h) power that uniquely enabled anticipation of the LH surge at least 2 days prior to its onset in 100% of individuals. Together, the present findings reveal fluctuations in distal body temperature and heart rate variability that consistently anticipate the LH surge, suggesting that automated ultradian rhythm monitoring may provide a novel and convenient method for non-invasive fertility assessment.

This blood spot assay for 25(OH)D(2) and 25(OH)D(3) provides a convenient and cost-effective alternative to serum assays and can be automated. This may be valuable in large-scale screening for risk of type 1 diabetes, for cardiometabolic risk screening, and for monitoring vitamin D supplementation.

Background Measuring concentrations of metabolites of estradiol and progesterone in urine, instead of measuring serum concentrations, is common in research and also is used in patient care. The primary aim of this study was to demonstrate that analysis of urine samples dried on filter paper by gas chromatography with tandem mass spectrometry (GC–MS/MS) provides results similar to serum analyzed by radioimmunoassay (RIA). Secondary aims were to show that collection of four samples during the day (4-spot method) can be substituted for a 24-h collection, and that analysis of urine from dried samples is equivalent to liquid urine samples. Methods This prospective observational study compared results of urine and serum analyses. Urine samples from women throughout the menstrual cycle and single samples from postmenopausal women were evaluated. Urine was collected onto filter paper and dried. Dried urine was extracted, hydrolyzed, and derivatized prior to analysis by GC–MS/MS. Hormone concentrations were normalized to creatinine. Single samples were used to compare results of 24-h urine collection to the 4-spot method from a separate population of women and men. A subset of these samples were used to compare results from dried urine to liquid urine. Results The primary study showed good reliability in the comparisons between the dried urine and serum assays. During the menstrual cycles of a subset of four women, urine metabolite concentrations followed the same pattern as serum concentrations. Comparison of 4-spot to 24-h urine collections and of dried to liquid urine measurements had intraclass correlation coefficients (ICC) greater than 0.95, indicating excellent agreement. Conclusions For estradiol and progesterone, the dried urine assay is a good surrogate for serum testing. The 4-spot method can be used instead of 24-h urine collections and dried urine results are comparable to liquid urine. The dried urine assay is useful for some clinical assessments of hormone disorders and may be useful in large epidemiologic studies due to ease of sample handling. Electronic supplementary material The online version of this article (10.1186/s13065-019-0539-1) contains supplementary material, which is available to authorized users.