Interactions between Paracetamol and Formaldehyde: Theoretical Investigation and Topological Analysis.

In this work, noncovalent interactions including hydrogen bonds, C···C, N···O, and van der Waals forces between paracetamol and formaldehyde were investigated using the second-order perturbation theory MP2 in conjunction with the correlation consistent basis sets (aug-cc-pVDZ and aug-cc-pVTZ). Two molecular conformations of paracetamol were considered. Seven equilibrium geometries of dimers were found from the result of the interactions with formaldehyde for each conformation of paracetamol. Interaction energies of complexes with both ZPE and BSSE corrections range from -7.0 to -21.7 kJ mol-1. Topological parameters (such as electron density, its Laplacian, and local electron energy density at the bond critical points) of the bonds from atoms in molecules theory were analyzed in detail. The natural bond orbital analysis showed that the stability of complexes was controlled by noncovalent interactions including O-H···O, N-H···O, C-H···O, C-H···N, C-H···H-C, C···C, and N···O. The red- and blue-shifted hydrogen bonds could both be observed in these complexes. The properties of these interactions were also further examined in water using a polarized continuum model. In water, the stability of the complex was slightly reduced as compared to that in the gas phase.

Moving towards sustainable coastal adaptation: Analysis of hydrological drivers of saltwater intrusion in the Vietnamese Mekong Delta.

Coastal lowlands are of particular importance in providing food, shelter, and livelihoods for large populations; yet aggravating effects caused by human activities and climate change have exposed these areas to multiple challenges. Located in the southernmost part of the Lower Mekong Basin, the Vietnamese Mekong Delta (VMD) is adversely affected by upstream hydropower development, localised water-engineering systems (dykes), climatic factors, and sea level rise. This paper examines how these drivers shape the adaptation strategies of rural communities in the coastal areas. Using mixed sources of historical measured data, numerical modelling and qualitative data gathered in three coastal provinces (Ben Tre, Tra Vinh, and Soc Trang), we find that hydrological alterations are manipulated by various drivers with more immediate effects of the tidal systems and sea level rise in the Vietnamese East Sea. The study results suggest that while these impacts are not adequately addressed by delta-scale measures, a mixed policy approach including control and adaptation measures has been adopted to tackle saltwater intrusion on the local scale. The paper provides a holistic insight into the complex temporal-spatial dimensions of hydrological change which have distressed coastal agroecosystems and resource-dependent communities. The paper argues that while voicing concerns over transboundary hydropower impacts is essential, in situ collaborative efforts among salinity-affected jurisdictions are equally important in addressing high uncertainty and complexity of saltwater intrusion in the future.

The accuracy of tuberculous meningitis diagnostic tests using Bayesian latent class analysis.

INTRODUCTION: Tuberculous meningitis (TBM) is the most dangerous form of tuberculosis with high mortality and disability rates. However, the delayed diagnostic process is often due to the absence of the gold standard tests leading to a lack of information about the sensitivity and specificity of diagnostic tests. This study aims to estimate the prevalence of TBM and determine the performance of four diagnostic procedures: the mycobacteria growth culture test, Gene Xpert assay, and analysis of protein levels and leukocyte count taken from cerebrospinal fluid. METHODOLOGY: We used a Bayesian latent class analysis to estimate the prevalence of TBM with 95% credible interval (CI), and the specificity and sensitivity of the four diagnostic procedures. The area under the receiver operating characteristic curve (AUC) of the cerebrospinal protein levels and leukocyte count were also compared and estimated using different thresholds. RESULTS: A total of 1,213 patients suspected of having TBM were included. The estimated TBM prevalence was 34.8 % (95% CI: 28.8 - 41.3). The sensitivity of culture test and Gene Xpert assay was 62.7% (95% CI: 52.5 - 74.0), and 57.5% (95% CI: 51.0 - 64.0), and the specificity of Gene-Xpert was 95. 9% (95% CI: 92.0 - 99.8). The AUC for leukocyte count was 76.0%, and for protein level was 73.4%. CONCLUSIONS: This study provided better information about the performance of four routine diagnostic tests and the prevalence of TBM which can enhance disease control and improve treatment outcomes.

Single-Port Laparoscopic Repair of Perforated Duodenal Ulcers.

BACKGROUND: Laparoscopic single-port surgery has widely been introduced for the treatment of various abdominal conditions. But controversies still exist regarding its potential advantages and risks, especially for emergency surgery. The aim of this study was to evaluate the results of a single-port laparoscopic repair using straight laparoscopic instruments for the treatment of perforated duodenal ulcers. METHODS: A prospective consecutive case series was conducted including all patients with a perforated duodenal ulcer who underwent a laparoscopic single-port repair at a single institution from January 2012 to June 2018. The operation was performed through a single port using conventional straight laparoscopic instruments and intra-corporeal knot tying techniques. RESULTS: Out of 75 patients, simple closure of the perforation without omental patch was accomplished in 96% of cases. Conversion to an open operation was required in one patient (1.3%) due to a posterior duodenal perforation, and additional trocar placement was needed in another patient (1.3%). The mean incision length was 2.0 ± 0.2 cm. The mean operation time was 63.0 ± 26.6 min. Meantime a nasogastric tube remained in place was 2.9 ± 0.8 days. Mean duration of analgesic use was 2.8 ± 0.8 days. The rate of postoperative complications was 2.7%, including two patients with wound infections. There were no instances of intestinal leak or abscess. The postoperative hospital stay was 5.7 ± 1.2 days. CONCLUSION: Laparoscopic single-port repair using conventional straight laparoscopic instruments with intra-corporeal knot tying technique was safe and feasible for patients with perforated duodenal ulcers with low risk factors. This method offers results comparable to those expected with the standard multiport laparoscopic approach with the addition of improved cosmetic outcomes.

Physiological characterization of poly-ß-hydroxybutyrate accumulation in the moderately thermophilic hydrogen-oxidizing bacterium Hydrogenophilus thermoluteolus TH-1.

Hydrogenophilus thermoluteolus strain TH-1 is a thermophilic hydrogen-oxidizing microorganism that has the highest growth rate among autotrophs. Genomic analysis revealed that this strain comprises the complete gene set for poly-ß-hydroxybutyrate (PHB) synthesis, i.e., three copies of acetyl-CoA acetyltransferase and polyhydroxyalkanoate synthase and one copy of acetoacetyl-CoA reductase and 3-hydroxyacyl-CoA dehydrogenase/3-hydroxybutyryl-CoA epimerase. An investigation on PHB accumulation in strain TH-1 demonstrated that PHB accumulation was induced by nitrogen limitation under autotrophic as well as heterotrophic conditions. This strain accumulated up to 430.4 ± 14.3 mg L-1 PHB during a 3-h incubation under nitrogen-limited heterotrophic conditions. The highest PHB accumulation rates under autotrophic and heterotrophic conditions were 38.6% (w/w) of the dry cells after a 6-h induction and 53.8% after 3 h, respectively. Although PHB granules started to accumulate after 15 min of nitrogen limitation under heterotrophic conditions, a drastic decrease of PHB was observed after 9 h of induction.

Sinistroposition: A case report of true left-sided gallbladder in a Vietnamese patient.

INTRODUCTION: Left-sided gallbladder without situs viscerum inversus (LSG-woSVI) is defined as a gallbladder located under the left lobe of the liver; to the left of the round/falciform ligament, but with all other viscera maintaining normal anatomical relationships. This is a rare congenital anomaly with a reported prevalence that ranges from 0.04% to 1.1%. It is usually an incidental intraoperative finding, and can be associated with anatomic abnormalities of the biliary tree, portal system and vasculature. LSG and associated variations may present significant challenges even for experienced surgeon. PRESENTATION OF CASE: LSG-woSVI was unexpectedly discovered in a 49-year-old, Vietnamese female during laparoscopic cholecystectomy. There were no pre-operative indications of sinistroposition. The cystic duct joined the common hepatic duct on the right side, and the cystic artery crossed anterior to the common bile duct in a right-to-left direction. Antegrade cholecystectomy was performed without intraoperative or postoperative complications. DISCUSSION: LSG is a rare anatomical variation that often remains undetected with ultrasound and pre-operative tests. Several hypotheses suggest underlying embryologic mechanisms for LSG and associated anomalies in ductal, portal and vascular anatomy, but the exact cause remains a mystery. Safe laparoscopic cholecystectomy can be done; however, there is an increased risk of injury to the major biliary structures compared to orthotopic gallbladder. CONCLUSION: Laparoscopic antegrade cholecystectomy is feasible for LSG. However, surgeons need to be cognizant of anatomy, so that rapid modifications of surgical technique can ensure positive patient outcomes.

First-trimester combined screening for Down syndrome: prediction of low birth weight, small for gestational age and pre-term delivery in a cohort of non-selected women.

OBJECTIVE: To establish the relationship between the first-trimester screening markers [pregnancy-associated plasma protein A (PAPP-A), free human chorionic gonadotrophin-beta (beta-hCG), nuchal translucency (NT)], the Down syndrome (DS) risk estimate, and the adverse outcomes such as low birth weight, small for gestational age (SGA) and pre-term delivery. METHODS: A retrospective cohort study including 1,734 non-selected singleton pregnancies consecutively enrolled into the programme of first-trimester combined screening for DS in a 12-month period at a single centre. Data from the Prenatal Patient Registry in ASTRAIA were combined with the Danish National Newborn Screening Registry and Danish Birth Registry. RESULTS: There was a significant relation between low PAPP-A MoM, low beta-hCG MoM, increased risk estimate for DS and low birth weight and SGA. Low PAPP-A MoM and increased NT showed a significant relation to pre-term and spontaneous pre-term delivery. Low PAPP-A MoM showed a significant relation to early pre-term delivery. CONCLUSION: First-trimester screening markers exhibited a significant relation to low birth weight, SGA and to some extent, to pre-term and early pre-term delivery. The screening performance of individual markers was poor.