Performance of Xpert® MTB/RIF and Xpert® Ultra for the diagnosis of tuberculous meningitis in children.

OBJECTIVE: To assess Xpert® MTB/RIF (Xpert) and Xpert® MTB/RIF Ultra (Ultra) performance in diagnosing pediatric tuberculous meningitis (TBM).METHODS: We conducted a study among children with suspected meningoencephalitis in Pune, India. Clinical, radiological, laboratory, and treatment data were analyzed to classify disease as definite, probable, possible or no TBM, using microbiologic or composite reference standards. We tested cerebrospinal fluid (CSF) either using Xpert or Ultra and estimated test performance characteristics.RESULTS: Of 341 participants, 149 (43.7%) were tested using Ultra and 192 (56.3%) with Xpert. Ultra had higher sensitivity (50% vs. 18%), lower specificity (91% vs. 99%), poor positive predictive value (PPV) (13% vs. 75%), and higher negative predictive value (NPV) (99% vs. 93%) than Xpert using the composite reference standard, with similar results by the microbiologic reference standard. Of 10 participants with trace positivity on Ultra, none met clinical TBM definitions.CONCLUSION: This is the first study to report on diagnostic performance of Ultra in pediatric TBM, which showed higher sensitivity and NPV than Xpert. For children presenting with nonspecific clinical features, Ultra is a promising diagnostic test. Further studies are required to define its optimal clinical use, including interpretation of trace positive results.

Concomitant pulmonary disease is common among patients with extrapulmonary TB.

BACKGROUND: Microbiologic screening of extrapulmonary TB (EPTB) patients could inform recommendations for aerosol precautions and close contact prophylaxis. However, this is currently not routinely recommended in India. Therefore, we estimated the proportion of Indian patients with EPTB with microbiologic evidence of pulmonary TB (PTB).METHODS: We characterized baseline clinical, radiological and sputum microbiologic data of 885 adult and pediatric TB patients in Chennai and Pune, India, between March 2014 and November 2018.RESULTS: Of 277 patients with EPTB, enhanced screening led to the identification of 124 (45%) with concomitant PTB, including 53 (19%) who reported a cough >2 weeks; 158 (63%) had an abnormal CXR and 51 (19%) had a positive sputum for TB. Of 70 participants with a normal CXR and without any cough, 14 (20%) had a positive sputum for TB. Overall, the incremental yield of enhanced screening of patients with EPTB to identify concomitant PTB disease was 14% (95% CI 12-16).CONCLUSIONS: A high proportion of patients classified as EPTB in India have concomitant PTB. Our results support the need for improved symptom and CXR screening, and recommends routine sputum TB microbiology screening of all Indian patients with EPTB.

Unhealthy alcohol use independently associated with unfavorable TB treatment outcomes among Indian men.

BACKGROUND: Approximately 10% of incident TB cases worldwide are attributable to alcohol. However, evidence associating alcohol with unfavorable TB treatment outcomes is weak.METHODS: We prospectively evaluated men (≥18 years) with pulmonary TB in India for up to 24 months to investigate the association between alcohol use and treatment outcomes. Unhealthy alcohol use was defined as a score of ≥4 on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) scale at entry. Unfavorable TB treatment outcomes included failure, recurrence, and all-cause mortality, analyzed as composite and independent endpoints.RESULTS: Among 751 men, we identified unhealthy alcohol use in 302 (40%). Median age was 39 years (IQR 28-50); 415 (55%) were underweight (defined as a body mass index [BMI] <18.5 kg/m²); and 198 (26%) experienced an unfavorable outcome. Unhealthy alcohol use was an independent risk factor for the composite unfavorable outcome (adjusted incidence rate ratio [aIRR] 1.47, 95% CI 1.05-2.06; P = 0.03) and death (aIRR 1.90, 95% CI 1.08-3.34; P = 0.03), specifically. We found significant interaction between AUDIT-C and BMI; underweight men with unhealthy alcohol use had increased risk of unfavorable outcomes (aIRR 2.22, 95% CI 1.44-3.44; P < 0.001) compared to men with BMI ≥18.5 kg/m² and AUDIT-C <4.CONCLUSION: Unhealthy alcohol use was independently associated with unfavorable TB treatment outcomes, highlighting the need for integrating effective alcohol interventions into TB care.

A Rare Case of Large Left Lateral Wall Vaginal Myoma.

Vaginal leiomyomas are rare, they are uncommon benign tumor with variable clinical presentation. They usually present as a mass per vaginum or dyspareunia or pressure symptoms on the neighbouring structures. We present a case of 47 years lady with mass per vaginum and difficulty in walking and chronic pelvic pain. Her clinical findings suggested a large mass in the left vaginal wall, the mass was approximately 12 x 10 cm in size hindering the visualization of the cervix. Her ultrasonography showed bulky uterus with mass occupying the cervix. This finding was not correlating with the clinical findings. Magnetic resonance imaging (MRI) was done and it was reported as mass lesion in pelvis separate from the cervix abutting the rectum posteriorly. Ultrasonography (USG) guided biopsy was done which was reported as Leiomyoma. She underwent vaginal myomectomy and was confirmed in histopathology as Leiomyoma. A leiomyoma is a smooth muscle tumor that arises from the muscular part of the uterus and rarely seen in the vaginal wall.

Global forest restoration and the importance of prioritizing local communities.

Forest restoration occupies centre stage in global conversations about carbon removal and biodiversity conservation, but recent research rarely acknowledges social dimensions or environmental justice implications related to its implementation. We find that 294.5 million people live on tropical forest restoration opportunity land in the Global South, including 12% of the total population in low-income countries. Forest landscape restoration that prioritizes local communities by affording them rights to manage and restore forests provides a promising option to align global agendas for climate mitigation, conservation, environmental justice and sustainable development.

Assessment of the Xpert assay among adult pulmonary tuberculosis suspects with and without diabetes mellitus.

SETTING: Pune and Pimpri-Chinchwad Municipal Corporation area, Maharashtra State, India.OBJECTIVE: To assess the sensitivity and specificity of the Xpert® MTB/RIF assay among adults with suspected pulmonary tuberculosis (PTB) and with or without diabetes (DM).DESIGN: As part of a prospective cohort study, we screened 2359 adults presumed to have PTB with no history of TB. All individuals underwent testing for two sputum smears, culture, Xpert, glycated haemoglobin and fasting blood sugar. We calculated sensitivity and specificity of Xpert by comparing it with TB sputum culture result as a gold standard.RESULTS: Among screened individuals, 483 (20%) were diagnosed with DM and 1153 (49%) with pre-DM; 723 (31%) had no DM. Overall sensitivity of Xpert was 96% (95%CI 95-97) and specificity was 91% (95%CI 89-93). Xpert sensitivity was significantly higher among DM group (98%) than in the 'No DM' (95%; P < 0.01) and pre-DM (96%; P < 0.05) groups. Among sputum smear-negative individuals, Xpert sensitivity was higher in the DM group than in the No DM (92% vs. 82%; P = 0.054) and pre-DM group (92% vs. 82%; P = 0.037).CONCLUSION: High sensitivity and specificity of Xpert underscores the need for its rapid scale up for the early detection of TB in settings with a high dual burden of TB and DM.

Clinical Estimation of Fetal Weight with Reference to Johnson's Formula: An Alternative Solution Adjacent to Sonographic Estimation of Fetal Weight.

Background Fetal weight estimation plays a significant role in the antenatal management of high risk pregnancies. It is also an important parameter for predicting the neonatal outcome and informs decision for the mode of intra-partum management of the pregnant women. Among the various methods of prenatal fetal weight estimation, the most commonly used are clinical estimation and sonography. Objective The objective of this study was to compare the accuracy of clinical estimation of fetal weight using Johnson's formula and sonographic estimation with actual birth weight. Method This prospective study was conducted at Dhulikhel Hospital, Kathmandu University Hospital, from January 2017 to August 2018. The study included 335 pregnant women at term gestation. Result The estimation of fetal weight at term pregnancy using Johnson's formula is as effective as sonological method. For clinical method, the fetal weight falls between 95 gm and 183 gm at 95% confidence interval. With respect to ultrasound method, the fetal weight is found to be 45 gm and 132 gm at 95% confidence interval at p value < 0.001. Conclusion Clinical estimation of fetal weight can be utilized as an alternative to sonological estimation in the management of labor and delivery. Johnson's formula is a simple, easy, cost-effective, and universally applicable method to predict fetal birth weight and can be used anywhere by doctors, nurses, midwives and paramedics in centers where ultrasound is not available.

The Study of Burden of Family Caregivers of Patients Living with Psychiatric Disorders in Remote Area of Nepal.

Background Family caregivers of psychiatric disorders likely to face burden. There is a paucity of data regarding the caregiver burden in psychiatric disorders in context of Nepal. Objective To study the caregiver burden in families with psychiatric illness and to find association between socio-demographic variables and caregiver burden in families with psychiatric illness. Method This is an analytical cross-sectional study. The participants (n=96) were caregiver of patients visiting outpatient department of two government of Nepal primary health care centers namely, Panchkhal Primary Health Care Center (PHC) Kavre District and Barhabise Health Care Center Sindhupalchowk district. The sample size has been determined by using statistical formula. Family burden assessment schedule (FBIS) was used for the study. Result The majority of the caregivers were females 56.3%. Most of the caregivers were aged below 45 years 54.2%. The large number of participants were single or separated 74%. The mean score of family burden assessment schedule was 27 ± 9.8 (range 0 to 48) with positive rate of 59.4%.Among the objective burden domains disruption of family leisure 61.5% was the most frequently reported burden. The subjective burden was reported in 95%. There were significant differential demographic associations with different domains of caregivers' burden. Conclusion Caregivers of Psychiatric patients experience different kind of burden of care. Our findings highlight the support to the family members to reduce their burden.

Respiratory health status is associated with treatment outcomes in pulmonary tuberculosis.

The association between respiratory impairment and tuberculosis (TB) treatment outcomes is not clear. We prospectively evaluated respiratory health status, measured using the Saint George's Respiratory Questionnaire (SGRQ), in a cohort of new adult pulmonary TB cases during and up to 18 months following treatment in India. Associations between total SGRQ scores and poor treatment outcomes of failure, recurrence and all-cause death were measured using multivariable Poisson regression. We enrolled 455 participants contributing 619 person-years at risk; 39 failed treatment, 23 had recurrence and 16 died. The median age was 38 years (interquartile range 26-49); 147 (32%) ever smoked. SGRQ scores at treatment initiation were predictive of death during treatment (14% higher risk per 4-point increase in baseline SGRQ scores, 95%CI 2-28, P = 0.01). Improvement in SGRQ scores during treatment was associated with a lower risk of failure (1% lower risk for every per cent improvement during treatment, 95%CI 1-2, P = 0.05). Clinically relevant worsening in SGRQ scores following successful treatment was associated with a higher risk of recurrence (15% higher risk per 4-point increase scores, 95%CI 4-27, P = 0.004). Impaired respiratory health status was associated with poor TB treatment outcomes. The SGRQ may be used to monitor treatment response and predict the risk of death in pulmonary TB. .

A comparative study of prevalence and spatial distribution of major Anopheline vector fauna in a hyper- and a hypomalaria endemic district of Odisha, India with special reference to onset of first wet season.

The state's retrospective findings indicate the incidence of malaria deaths, which is more during the onset of first monsoon season. Based upon this fact, our objective was to study the distribution pattern of major Anopheles vectors in two endemic districts viz. Kalahandi and Cuttack of Odisha, India that differ significantly according to malariogenic stratification, under the impact of first monsoon shower. A comparative study of vector abundance, predominance, their habitats, resting site preference, impact of abiotic rhythm (light/dark period) on vector distribution, gonotrophic status as well as sporozoite rate was established in a high and a low endemic district of Odisha, when the degree of malaria transmission elevates to its peak level Anopheles culicifacies was found to be predominant in hyperendemic Kalahandi district while Anopheles subpictus was abundant in hypo-endemic Cuttack district. Both primary vector An. culicifacies and the secondary vector An. subpictus mostly prefer CS (Cattle shed) compared to HD (Human dwelling) in Kalahandi district where as there was slight shifting of resting habitat of An. culicifacies from CS to HD in Cuttack district. Anopheles culicifacies prefers to rest on wall besides objects in Kalahandi while no such site preference was observed in Cuttack district. On the other hand, distribution of An. subpictus was highly influenced by the daily rhythm of light/dark cycle (i.e. day and night) in Cuttack. The gonotrophic condition revealed the high tendency of the predominant vectors towards endophilic resting. The sporozoite rate was 0.66% in Kalahandi and nil in Cuttack district. The proper monitoring of vector prevalence and distribution, at least during the peak transmission period can avert a perpetuated upsurge in malaria.

Perennial malaria transmission and its association with rainfall at Kalahandi district of Odisha, Eastern India: A retrospective analysis.

India contributes substantially to global malaria incidents. Vector dynamics is the significant determinant of malaria risk. Hence, knowledge on the interaction between rainfall, malaria cases and malaria vector density can be very useful for controlling malaria transmission. Kalahandi was screened for malaria cases, Anopheline vector density and their temporal relationship with rainfall. Epidemiological data was obtained from National Vector Borne Disease Control Programme, Odisha, India. Three years vector population study was carried out. Rainfall data was obtained from a database maintained by the Govt. of Odisha and was analysed using Univariate ANOVA and Pearson correlation co-efficient tests using R-prog. Malaria was found to be prevalent throughout the year attaining peak between July to August and another peak in December, amidst which the clinical malaria cases being recorded implied highest incidents in the month of July. The results estimated the seasonality of the population of An. culicifacies, An. fluviatilis and An. annularis over the region and determined the influence of rainfall on the vector population dynamics. Simple linear regression analysis suggested that at one month lag monthly rainfall (P=0.0007) was a significant meteorological factor. Rainfall seemed to be one of the best malaria predictors because of its positive correlation with proliferation of malaria cases in conjunction with An. culicifacies density making malaria a serious health issue in Kalahandi.

A comparative study of prevalence and spatial distribution of major Anopheline vector fauna in a hyper- and a hypomalaria endemic district of Odisha, India with special reference to onset of first wet season

@#The state’s retrospective findings indicate the incidence of malaria deaths, which is more during the onset of first monsoon season. Based upon this fact, our objective was to study the distribution pattern of major Anopheles vectors in two endemic districts viz. Kalahandi and Cuttack of Odisha, India that differ significantly according to malariogenic stratification, under the impact of first monsoon shower. A comparative study of vector abundance, predominance, their habitats, resting site preference, impact of abiotic rhythm (light/dark period) on vector distribution, gonotrophic status as well as sporozoite rate was established in a high and a low endemic district of Odisha, when the degree of malaria transmission elevates to its peak level Anopheles culicifacies was found to be predominant in hyperendemic Kalahandi district while Anopheles subpictus was abundant in hypo-endemic Cuttack district. Both primary vector An. culicifacies and the secondary vector An. subpictus mostly prefer CS (Cattle shed) compared to HD (Human dwelling) in Kalahandi district where as there was slight shifting of resting habitat of An. culicifacies from CS to HD in Cuttack district. Anopheles culicifacies prefers to rest on wall besides objects in Kalahandi while no such site preference was observed in Cuttack district. On the other hand, distribution of An. subpictus was highly influenced by the daily rhythm of light/dark cycle (i.e. day and night) in Cuttack. The gonotrophic condition revealed the high tendency of the predominant vectors towards endophilic resting. The sporozoite rate was 0.66% in Kalahandi and nil in Cuttack district. The proper monitoring of vector prevalence and distribution, at least during the peak transmission period can avert a perpetuated upsurge in malaria.

Perennial malaria transmission and its association with rainfall at Kalahandi district of Odisha, Eastern India: A retrospective analysis

@#India contributes substantially to global malaria incidents. Vector dynamics is the significant determinant of malaria risk. Hence, knowledge on the interaction between rainfall, malaria cases and malaria vector density can be very useful for controlling malaria transmission. Kalahandi was screened for malaria cases, Anopheline vector density and their temporal relationship with rainfall. Epidemiological data was obtained from National Vector Borne Disease Control Programme, Odisha, India. Three years vector population study was carried out. Rainfall data was obtained from a database maintained by the Govt. of Odisha and was analysed using Univariate ANOVA and Pearson correlation co-efficient tests using R-prog. Malaria was found to be prevalent throughout the year attaining peak between July to August and another peak in December, amidst which the clinical malaria cases being recorded implied highest incidents in the month of July. The results estimated the seasonality of the population of An. culicifacies, An. fluviatilis and An. annularis over the region and determined the influence of rainfall on the vector population dynamics. Simple linear regression analysis suggested that at one month lag monthly rainfall (P=0.0007) was a significant meteorological factor. Rainfall seemed to be one of the best malaria predictors because of its positive correlation with proliferation of malaria cases in conjunction with An. culicifacies density making malaria a serious health issue in Kalahandi.

Trends in HbA1c levels and implications for diabetes screening in tuberculosis cases undergoing treatment in India.

SETTING: The optimal timing of screening for diabetes mellitus (DM) among tuberculosis (TB) cases is unclear due to the possibility of stress hyperglycemia. DESIGN: We evaluated adult (18 years) pulmonary TB cases at treatment initiation as well as at 3 months, 6 months and 12 months. DM was identified by self-report (known DM) or glycated hemoglobin (HbA1c)  6.5% (new DM). Trends in HbA1c levels during treatment were assessed using non-parametric tests. RESULTS: Of the 392 participants enrolled, 75 (19%) had DM, 30 (40%) of whom had new DM. Of the 45 participants with known DM, respectively 37 (82%) and 40 (89%) received medication to lower glucose levels at treatment initiation and completion; one participant with new DM initiated glucose-lowering medication during follow-up. The median HbA1c level in participants with known, new and no DM was respectively 10.1% (interquartile range [IQR] 8.3-11.6), 8.5% (IQR 6.7-11.5) and 5.6% (IQR 5.3-5.9) at treatment initiation, and 8.7% (IQR 6.8-11.3), 7.1% (IQR 5.8-9.5) and 5.3% (IQR 5.1-5.6) at treatment completion (P < 0.001). Overall, 5 (12%) with known and 13 (43%) with new DM at treatment initiation had reverted to HbA1c < 6.5% by treatment completion (P = 0.003); the majority of reversions occurred during the first 3 months, with no significant reversions beyond 6 months. CONCLUSION: HbA1c levels declined with anti-tuberculosis treatment. Repeat HbA1c testing at treatment completion could reduce the risk of misdiagnosis of DM.

Diabetes and pre-diabetes among household contacts of tuberculosis patients in India: is it time to screen them all?

SETTING: Pre-diabetes mellitus (pre-DM) and DM increase the risk of developing tuberculosis (TB). Screening contacts of TB patients for pre-DM/DM and linking them to care may mitigate the risk of developing TB and improve DM management. OBJECTIVE: To measure the prevalence of pre-DM/DM and associated factors among the adult household contacts (HHCs) of pulmonary TB patients. METHODS: Between August 2014 and May 2017, adult HHCs of newly diagnosed adult PTB patients in Pune and Chennai, India, had single blood samples tested for glycosylated haemoglobin (HbA1c) at enrolment. DM was defined as previously diagnosed, self-reported DM or HbA1c 6.5%, and pre-DM as HbA1c between 5.7% and 6.4%. Latent tuberculous infection (LTBI) was defined as a positive tuberculin skin test (5 mm induration) or QuantiFERON® Gold In-Tube (0.35 international units/ml). RESULTS: Of 652 adult HHCs, 175 (27%) had pre-DM and 64 (10%) had DM. Forty (64%) HHCs were newly diagnosed with DM and 48 (75%) had poor glycaemic control (HbA1c 7.0%). Sixty-eight (22%) pre-DM cases were aged 18-34 years. Age 35 years, body mass index 25 kg/m2, chronic disease and current tobacco smoking were significantly associated with DM among HHCs. CONCLUSIONS: Adult HHCs of TB patients in India have a high prevalence of undiagnosed DM, pre-DM and LTBI, putting them at high risk for developing TB. Routine DM screening should be considered among all adult HHCs of TB.

Temperature Controlled Evolution of Silver Polypods from Biomass Encapsulated Nano-Droplets.

Silver nanoparticles are produced by a novel biosynthesis technique using fungus Penicillium purpurogenum NPMF (MTCC 7356). The biomass when subjected to heat treatment up to 700 °C produces the nanoparticles of silver due to the presence of free carbon which acts as encapsulation for silver nanoparticles. Increase in temperature above 700 °C causes a reduction in concentration of free carbon so that the nanoparticles come close to each other and form clusters in the shape of tetrapods to polypods. The micro-Raman analysis supports the formation of mesoporous carbon with increase in the calcined temperature. The formation of Ag nanostructures has been explained in terms of free energy diagram i.e., the crystal favors more to grow on (100) facet or (110) facet rather than on (111) facet by the addition of silver atoms and thereby, it releases more energy. The release of energy has been confirmed from the differential thermo gravimetric analysis. In fact, it is the dynamics of the minimization of the free energy of the system which governs the reorientation and rearrangement of Ag themselves leading to formation of various types of polypods. A formation mechanism is presented schematically.

Metal-induced aggregation of valine capped gold nanoparticles: An efficient and rapid approach for colorimetric detection of Pb2+ ions.

In this study, we report a novel application of valine-capped gold nanoparticles for colorimetric and visual detection of lead ions. The -COO- group of the hydrophobic valine molecules present efficient electrostatic repulsion resulting in generation of stable, well-dispersed and size-controlled GNPs. The GNPs were highly selective for Pb2+ ions and showed visible colour change in the assay mixture on addition of solution containing lead ions. Interestingly, a decrease in the intensity of original SPR peak at 530 nm was observed, with concomitant appearance of a new peak at longer wavelength due to agglomerated GNPs. The free -COO- groups on GNP surface interacted with Pb2+ and ion-dependent chelation mechanism lead to cross-linking of particles and subsequent agglomeration. Binding of Pb2+ ions and valine-capped GNPs occur in a stochiometric ratio of 1:2. The GNPs displayed colorimetric sensing in the range of 0 to 100 ppm concentration with a very high selectivity towards lead even in the presence of other metal ions. The minimum detection limit (MDL) for Pb2+ was 30.5 µM. We anticipate that these valine-capped GNPs may be employed for lead detection in polluted water/wastewater through a cost-efficient, one-step assay protocol as it does not require additional functionalization with specific ligand molecules.

Prevalence of dysglycemia and clinical presentation of pulmonary tuberculosis in Western India.

SETTING: Pune, India. OBJECTIVES: To estimate the prevalence and risk factors of pre-diabetes mellitus (DM) and DM, and its associations with the clinical presentation of tuberculosis (TB). DESIGN: Screening for DM was conducted among adults (age  18 years) with confirmed TB between December 2013 and January 2017. We used multinomial regression to evaluate the risk factors for pre-DM (glycated hemoglobin [HbA1c]  5.7-6.5% or fasting glucose 100-125 mg/dl) and DM (HbA1c  6.5% or fasting glucose  126 mg/dl or random blood glucose > 200 mg/dl or self-reported DM history/treatment) and the association of dysglycemia with the severity of TB disease. RESULTS: Among 1793 participants screened, 890 (50%) had microbiologically confirmed TB. Of these, 33% had pre-DM and 18% had DM; 41% were newly diagnosed. The median HbA1c level among newly diagnosed DM was 7.0% vs. 10.3% among known DM (P < 0.001). DM (adjusted OR [aOR] 4.94, 95%CI 2.33-10.48) and each per cent increase in HbA1c (aOR 1.42, 95%CI 1.01-2.01) was associated with >1+ smear grade or 9 days to TB detection. CONCLUSION: Over half of newly diagnosed TB patients had DM or pre-DM. DM and increasing dysglycemia was associated with higher bacterial burden at TB diagnosis, potentially indicating a higher risk of TB transmission to close contacts.

Molecular Characterization and Computational Modelling of New Delhi Metallo-ß-Lactamase-5 from an Escherichia coli Isolate (KOEC3) of Bovine Origin.

Emergence of antimicrobial resistance mediated through New Delhi metallo-ß-lactamases (NDMs) is a serious therapeutic challenge. Till date, 16 different NDMs have been described. In this study, we report the molecular and structural characteristics of NDM-5 isolated from an Escherichia coli isolate (KOEC3) of bovine origin. Using PCR amplification, cloning and sequencing of full blaNDM gene, we identified the NDM type as NDM-5. Cloning of full gene in E. coli DH5α and subsequent assessment of antibiotic susceptibility of the transformed cells indicated possible role of native promoter in expression blaNDM-5. Translated amino acid sequence had two substitutions (Val88Leu and Met154Leu) compared to NDM-1. Theoretically deduced isoelectric pH of NDM-5 was 5.88 and instability index was 36.99, indicating a stable protein. From the amino acids sequence, a 3D model of the protein was computed. Analysis of the protein structure elucidated zinc coordination and also revealed a large binding cleft and flexible nature of the protein, which might be the reason for broad substrate range. Docking experiments revealed plausible binding poses for five carbapenem drugs in the vicinity of metal ions. In conclusion, results provided possible explanation for wide range of antibiotics catalyzed by NDM-5 and likely interaction modes with five carbapenem drugs.

Atypical Exciton-Phonon Interactions in WS2 and WSe2 Monolayers Revealed by Resonance Raman Spectroscopy.

Resonant Raman spectroscopy is a powerful tool for providing information about excitons and exciton-phonon coupling in two-dimensional materials. We present here resonant Raman experiments of single-layered WS2 and WSe2 using more than 25 laser lines. The Raman excitation profiles of both materials show unexpected differences. All Raman features of WS2 monolayers are enhanced by the first-optical excitations (with an asymmetric response for the spin-orbit related XA and XB excitons), whereas Raman bands of WSe2 are not enhanced at XA/B energies. Such an intriguing phenomenon is addressed by DFT calculations and by solving the Bethe-Salpeter equation. These two materials are very similar. They prefer the same crystal arrangement, and their electronic structure is akin, with comparable spin-orbit coupling. However, we reveal that WS2 and WSe2 exhibit quite different exciton-phonon interactions. In this sense, we demonstrate that the interaction between XC and XA excitons with phonons explains the different Raman responses of WS2 and WSe2, and the absence of Raman enhancement for the WSe2 modes at XA/B energies. These results reveal unusual exciton-phonon interactions and open new avenues for understanding the two-dimensional materials physics, where weak interactions play a key role coupling different degrees of freedom (spin, optic, and electronic).