Combined FTIR/Raman spectroscopic studies and ab initio electronic structure calculations of Dithiothreitol

A total of seven minimum energy geometries were obtained on exploring the conformational landscape of dithiothreitol (DTT) by varying the prominent dihedral angles in the molecule through a relaxed scan with a step size of 5° at B3LYP/cc-pVTZ with further geometry optimization at CCSD/cc-pVDZ level of theory. Single point energies were calculated for all the conformers at CCSD(T)/CBS limit with cc-pVNZ (N = T, Q) level of theory and revealed the similar energy pattern. The two conformers, namely G'TG'1 and G'TT, were found iso-energic even though they differed in their structure significantly and were of the lowest energy compared to others. Energies corresponding to the cyclic as well as other configurational counterpart of the global minimum were found much higher in energy compared to the global minimum structure. Intramolecular sulfur centered hydrogen bond was seen to stabilize the global minimum structure of DTT as revealed by AIM, NBO, FMO and ESP charge analysis. Computed NMR of DTT matched well with the experimental data gleaned from the literature. Vibrational spectra (Raman and IR) were measured and compared with computed normal modes of DTT, which were found in good agreement.

Aerosol demasking enhances climate warming over South Asia

Anthropogenic aerosols mask the climate warming caused by greenhouse gases (GHGs). In the absence of observational constraints, large uncertainties plague the estimates of this masking effect. Here we used the abrupt reduction in anthropogenic emissions observed during the COVID-19 societal slow-down to characterize the aerosol masking effect over South Asia. During this period, the aerosol loading decreased substantially and our observations reveal that the magnitude of this aerosol demasking corresponds to nearly three-fourths of the CO2-induced radiative forcing over South Asia. Concurrent measurements over the northern Indian Ocean unveiled a ~7% increase in the earth's surface-reaching solar radiation (surface brightening). Aerosol-induced atmospheric solar heating decreased by ~0.4 K d-1. Our results reveal that under clear sky conditions, anthropogenic emissions over South Asia lead to nearly 1.4 W m-2 heating at the top of the atmosphere during the period March-May. A complete phase-out of today's fossil fuel combustion to zero-emission renewables would result in rapid aerosol demasking, while the GHGs linger on.

Nature and Strength of Sulfur-Centered Hydrogen Bond in Methanethiol Aqueous Solutions

Methanethiol (M) and water (W) clusters like dimers (M₁W₁, M₂, and W₂), trimers (M₁W₂, M₂W₁, M₃, and W₃), and tetramers (M₁W₃, M₂W₂, M₃W₁, M₄, and W₄) were studied to assess the strength of sulfur-centered hydrogen bonding using different levels of theories, viz, HF, MP2, MP3, MP4, B3LYP, B3LYP-D3, CCSD, CCSD(T)-F12, and CCSD(T) along with aug-cc-pVNZ (where N = D, T, and Q) basis sets. Interaction energies were found to be in the range of -3.3 to -5.3 kcal/mol for the dimers, -8.0 to -16.7 kcal/mol for the trimers, and -13.5 to -29.5 kcal/mol for the tetramers at the B3LYP-D3/CBS limit level of theory. Normal modes of vibrations computed at the B3LYP/cc-pVDZ level of theory were seen to be in good agreement with the experimental values. Local energy decomposition calculations using the DLPNO-CCSD(T) level of theory indicated the domination of electrostatic interactions' contribution to the interaction energy in all cluster systems. Furthermore, atoms in molecules and natural bond orbital calculations both carried out at the B3LYP-D3/aug-cc-pVQZ level of theory aided in visualizing the hydrogen bonds besides proving a rationale for the strength of the hydrogen bonds and thereby the stability of these cluster systems.

Scenedesmus obliquus and Chlorella vulgaris – A Prospective Algal Fuel Source

In recent years, the prospective use of algae as an alternate fuel source for petroleum-based fuels has increased drastically. It has been researched extensively and proven that it can be used as a sustainable feedstock for producing green energy considering environmental safety. This article focused on the economically viable algal feedstock for the production of lipid content for its use as a feedstock for biodiesel production. For this purpose, the algal species Scenedesmus obliquus and Chlorella vulgaris were selected, and it was grown under lab and open ambient conditions with two Blue green Medium (BG-11) and Bold Basal medium (BBM). Upon the yield, it was noticed that the BG-11 medium gave optimum lipid yield for both species. Hence, it was determined that through this medium higher lipid yield can be expected, and based on the GC-MS result it was notified that it can be a viable source of alternate fuel.

Behavior science led technology for financial wellness

Financial wellness is regarded as a significant constituent of the overall well-being of individuals. Financial wellbeing is defined as having financial security and freedom of choice, in the present and in the future. This has a direct correlation to overall wellbeing: including productivity experienced at work, quality of relationship, quality of health and hence quality of life. Financial wellness is also challenging as everyone desires to achieve a state of wellness while the pathways to its achievement are not straightforward and can be easily overwhelming to many. In the Indian context, recent reports point to the fact that financial wellness emerges as a top stressor for a majority of people which has also heightened due to the pandemic. A lack of financial wellness thus emerges as a major problem in the country. The prevalence of concerns on financial wellness in fact, is witnessed across the globe. An approach to ameliorating this is through the field of behavioral finance which has uncovered many behavioral biases and barriers which impact how financial decisions are taken. Examples include lack of awareness of financial needs or awareness of the right products, lack of self-control, confusion in making financial choices or being unable to save/invest at the right time. To address this, we present a holistic and hyper-personalized approach that combines technology and behavioral science to influence financial behavior. The solution aims at enhancing financial wellness of individuals using behavioral levers and nudges. This combines two aspects: (1) an engaging user interface at the front-end and (2) a customer insights/behavioral analytics and intervention recommendation system at the back end that suggests appropriate hyper-personalized actionable steps to the user. The solution helps users to visualize their financial needs, set financial goals and receive appropriate personalized nudges to help them in implementing financial plans as they go through various phases of career/life stages. We present our thoughts on how financial wellness can be extended to address financial inclusion in India.

Effects of fossil fuel and total anthropogenic emission removal on public health and climate

Anthropogenic greenhouse gases and aerosols are associated with climate change and human health risks. We used a global model to estimate the climate and public health outcomes attributable to fossil fuel use, indicating the potential benefits of a phaseout. We show that it can avoid an excess mortality rate of 3.61 (2.96-4.21) million per year from outdoor air pollution worldwide. This could be up to 5.55 (4.52-6.52) million per year by additionally controlling nonfossil anthropogenic sources. Globally, fossil-fuel-related emissions account for about 65% of the excess mortality, and 70% of the climate cooling by anthropogenic aerosols. The chemical influence of air pollution on aeolian dust contributes to the aerosol cooling. Because aerosols affect the hydrologic cycle, removing the anthropogenic emissions in the model increases rainfall by 10-70% over densely populated regions in India and 10-30% over northern China, and by 10-40% over Central America, West Africa, and the drought-prone Sahel, thus contributing to water and food security. Since aerosols mask the anthropogenic rise in global temperature, removing fossil-fuel-generated particles liberates 0.51(±0.03) °C and all pollution particles 0.73(±0.03) °C warming, reaching around 2 °C over North America and Northeast Asia. The steep temperature increase from removing aerosols can be moderated to about 0.36(±0.06) °C globally by the simultaneous reduction of tropospheric ozone and methane. We conclude that a rapid phaseout of fossil-fuel-related emissions and major reductions of other anthropogenic sources are needed to save millions of lives, restore aerosol-perturbed rainfall patterns, and limit global warming to 2 °C.

Endemic Indian clones of Klebsiella pneumoniae-harbouring New Delhi metallo-beta-lactamase-1 on a hybrid plasmid replicon type: A case of changing New Delhi metallo-beta-lactamase plasmid landscapes in India?

PURPOSE

blaNDM genes are MBL genes that confer resistance to carbapenems. Globally, they are associated with diverse clones and plasmids. In this study, we characterised three isolates of Klebsiella pneumoniae-harbouring blaNDM1 from patients undergoing chronic haemodialysis and renal transplantation.

MATERIALS AND METHODS

3 blaNDM1 -producing K. pneumoniae were isolated from end-stage renal disease patients undergoing haemodialysis and renal transplantation from a nephrology unit. All the three isolates were screened for clinically relevant resistant genes. Plasmid replicon content was analysed by polymerase chain reaction based replicon typing. Conjugation assays were done using azide-resistant Escherichia coli J53 as the recipient strain. Multilocus sequence typing and variable number tandem repeat typing were done to find the clonality. Replicon sequence based typing was attempted to find the diversity of replicon-associated sequences in IncHI3 plasmids.

RESULTS

All the 3 blaNDM positive isolates possessed the New Delhi metallo-beta-lactamase-1 (NDM-1) allele with an IncHI3 plasmid which was not transferable in one isolate. The isolates were found to be sequence type 14 (ST14; 2 nos) and ST38 both of which were previously reported to be the NDM-producing K. pneumoniae STs prevalent in India. Replicon sequence analysis revealed limited sequence diversity within the repHI3 and repFIB locus.

CONCLUSION

To the best of our knowledge, this is the first report of IncHI3, a newly assigned enterobacterial plasmid incompatibility group from India. This could either be a case of importation or a widely circulating NDM plasmid type in India.

Erratum: Endemic Indian clones of Klebsiella pneumoniae harbouring New Delhi metallo beta lactamase 1 on a hybrid plasmid replicon type: A case of changing New Delhi metallo beta lactamase plasmid landscapes in India?

[This corrects the article DOI: 10.4103/0255-0857.188314.].

Retention of laryngoscopy skills in medical students: a randomised, cross-over study of the Macintosh, A.P. Advance(™) , C-MAC(®) and Airtraq(®) laryngoscopes

In addition to being effective and easy to learn how to use, the ideal laryngoscope should be associated with minimal reduction in skill performance during gaps in practice over time. We compared the time taken to intubate the trachea of a manikin by novice medical students immediately after training, and then after 1 month, with no intervening practice. We designed a two-period, four-group, randomised, cross-over trial to compare the Macintosh, Venner(™) A.P. Advance(™) with difficult airway blade, C-MAC(®) with D-Blade and Airtraq(®) with wireless video-viewer. A bougie was used to aid intubation with the Macintosh and the C-MAC. After training, there was no significant difference in median (IQR [range]) intubation time using the videolaryngoscopes compared with the Macintosh, which took 30 (26.5-35 [12-118])s. One month later, the intubation time was longer using the C-MAC (41 (29.5-52 [20-119])s; p = 0.002) and A.P. Advance (40 (28.5-57.5 [21-107])s; p = 0.0003)m compared with the Macintosh (27 (21-29 [16-90])s); there was no difference using the Airtraq (27 (20.5-32.5 [15-94])s; p = 0.258) compared with the Macintosh. While skill acquisition after a brief period of learning and practice was equal for each laryngoscope, performance levels differed after 1 month without practice. In particular, the consistency of performance using the C-MAC and A.P. Advance was worse compared with the Macintosh and the Airtraq. While the clinical significance of this is doubtful, we believe that reliable and consistent performance at laryngoscopy is desirable; for the devices that we tested, this requires regular practice.

Reductions in indoor black carbon concentrations from improved biomass stoves in rural India

Deployment of improved biomass burning cookstoves is recognized as a black carbon (BC) mitigation measure that has the potential to achieve health benefits and climate cobenefits. Yet, few field based studies document BC concentration reductions (and resulting human exposure) resulting from improved stove usage. In this paper, data are presented from 277 real-world cooking sessions collected during two field studies to document the impacts on indoor BC concentrations inside village kitchens as a result of switching from traditional stoves to improved forced draft (FD) stoves. Data collection utilized new low-cost cellphone methods to monitor BC, cooking duration, and fuel consumption. A cross sectional study recorded a reduction of 36% in BC during cooking sessions. An independent paired sample study demonstrated a statistically significant reduction of 40% in 24 h BC concentrations when traditional stoves were replaced with FD stoves. Reductions observed in these field studies differ from emission factor reductions (up to 99%) observed under controlled conditions in laboratory studies. Other nonstove sources (e.g., kerosene lamps, ambient concentrations) likely offset the reductions. Health exposure studies should utilize reductions determined by field measurements inside village kitchens, in conjunction with laboratory data, to assess the health impacts of new cooking technologies.

Simultaneously mitigating near-term climate change and improving human health and food security

Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at $700 to $5000 per metric ton, which is well above typical marginal abatement costs (less than $250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide-reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.

Respiratory gated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) after breast conservative surgery for carcinoma of the breast: The Salmaniya Medical complex experience

PURPOSE

To present our clinical experience using SIB-IMRT Technique for Intact Breast cancer.

MATERIALS AND METHODS

A retrospective review of 45 cases of Stage I-IV breast cancer patients treated with SIB-IMRT with respiratory gating after Conservative treatments from 25th November 2008 to 16th February 2010. The most common fractionation was 1.8 Gy to Ipsilateral Breast tissue and 2.2 Gy to the lumpectomy cavity giving whole breast dose as 50.4 Gy and Lumpectomy cavity dose as 61.6 Gy over 28 fractions concomitantly. Respiratory gating was done and CT-images were taken in inspiratory breath hold position.

RESULTS

A total of 45 patients with breast cancer - stage I (17.7%), II (71%), III (8.9%), IV (2.2%) were treated with SIB- IMRT with respiratory gated radiotherapy. Out of 45 patients, 24 are of left sided breast cancer and 21 are of right sided breast cancer patients. The median, Dose maximum (D-max) in SIB-IMRT is 106.2% of prescribed lumpectomy site dose. The median isodose line prescribed to PTV-2 is 100%. The Conformity index (CI) is 0.9688 (median value) and Homogeneity index (HI) 1.06 (median). The median ipsilateral lung, mean dose is 21.66 Gy and V-20 is 37.4%. For left sided cases the median value of mean heart dose, V-30 and V-40 are 22.98 Gy, 23.45% and 9.45 % respectively. Acute skin toxicity was of Grade-I in 2.2 %, Grade-II in 64.4 %, Grade-III in 31.1 %, and Grade-IV in 2.2 %. The global Breast cosmoses were seen excellent in majority (93%) of case at median follow up of 8 months duration.

CONCLUSIONS

Breast SIB-IMRT Technique is feasible and comparable with other treatment techniques with reduced treatment duration by six fractions. At median follow up of 8 months the skin toxicity and cosmoses are excellent in high percentage of cases.

Efficacy of trypsin in enhancing assessment of bacterial colonisation of vascular catheters

Since the number of organisms isolated from a medical device is crucial in assessing the likelihood of device-associated infection, we examined whether incubation of catheters in trypsin before sonication can increase the yield of superficially colonised vascular catheters in vitro and those removed from patients. Polyurethane and silicone catheters were individually colonised in vitro with individual clinical isolates including Staphylococcus aureus and Escherichia coli. Equal numbers of 1 cm segments of colonised catheters were then individually incubated either in a trypsin-containing solution or a control solution without trypsin. Each solution containing the segment was then sonicated and cultured quantitatively. In the clinical arm, indwelling catheters removed from patients were also cut into 1 cm segments that were equally suspended in the trypsin-containing or control solution and then sonicated and cultured quantitatively. Trypsin-based sonication enhanced the detection of S. aureus on colonised polyurethane and silicone catheters in vitro by 14- and 30-fold, respectively (P = 0.03 and P = 0.04), and the detection of E. coli on colonised polyurethane and silicone catheters by 3- and 6-fold, respectively (P = 0.04 and P = 0.05). Compared with sonication alone, trypsin followed by sonication resulted in 10% increase in the detectability of significant colonisation of indwelling catheters removed from patients and 11% increase in the mean colony counts of colonising organisms (P = 0.04). Exposure of catheters to trypsin before sonication improves the sensitivity of sonication and enhances the accuracy of assessing significant catheter colonisation.

Novel H1N1-associated rhabdomyolysis leading to acute renal failure

The WHO recently declared that the novel influenza H1N1 virus was responsible for the 2009 flu pandemic. As the virus continues to spread globally and affect more individuals, more complications of infection with this virus are being recognized. To our knowledge, we report the first case of H1N1-induced rhabdomyolysis leading to acute renal failure in an adult. This case highlights the importance of recognizing a significant extrapulmonary complication of H1N1 infection.

Integrated model shows that atmospheric brown clouds and greenhouse gases have reduced rice harvests in India

Previous studies have found that atmospheric brown clouds partially offset the warming effects of greenhouse gases. This finding suggests a tradeoff between the impacts of reducing emissions of aerosols and greenhouse gases. Results from a statistical model of historical rice harvests in India, coupled with regional climate scenarios from a parallel climate model, indicate that joint reductions in brown clouds and greenhouse gases would in fact have complementary, positive impacts on harvests. The results also imply that adverse climate changes due to brown clouds and greenhouse gases contributed to the slowdown in harvest growth that occurred during the past two decades.