Al-alkyls as acceptor dopant precursors for atomic-scale devices

Atomically precise ultradoping of silicon is possible with atomic resists, area-selective surface chemistry, and a limited set of hydride and halide precursor molecules, in a process known as atomic precision advanced manufacturing (APAM). It is desirable to expand this set of precursors to include dopants with organic functional groups and here we consider aluminium alkyls, to expand the applicability of APAM. We explore the impurity content and selectivity that results from using trimethyl aluminium and triethyl aluminium precursors on Si(001) to ultradope with aluminium through a hydrogen mask. Comparison of the methylated and ethylated precursors helps us understand the impact of hydrocarbon ligand selection on incorporation surface chemistry. Combining scanning tunneling microscopy and density functional theory calculations, we assess the limitations of both classes of precursor and extract general principles relevant to each.

The stability of Cl-, Br-, and I-passivated Si(100)-(2 × 1) in ambient environments for atomically-precise pattern preservation

Atomic precision advanced manufacturing (APAM) leverages the highly reactive nature of Si dangling bonds relative to H- or Cl-passivated Si to selectively adsorb precursor molecules into lithographically defined areas with sub-nanometer resolution. Due to the high reactivity of dangling bonds, this process is confined to ultra-high vacuum (UHV) environments, which currently limits its commercialization and broad-based appeal. In this work, we explore the use of halogen adatoms to preserve APAM-derived lithographic patterns outside of UHV to enable facile transfer into real-world commercial processes. Specifically, we examine the stability of H-, Cl-, Br-, and I-passivated Si(100) in inert N₂and ambient environments. Characterization with scanning tunneling microscopy and x-ray photoelectron spectroscopy (XPS) confirmed that each of the fully passivated surfaces were resistant to oxidation in 1 atm of N₂for up to 44 h. Varying levels of surface degradation and contamination were observed upon exposure to the laboratory ambient environment. Characterization byex situXPS after ambient exposures ranging from 15 min to 8 h indicated the Br- and I-passivated Si surfaces were highly resistant to degradation, while Cl-passivated Si showed signs of oxidation within minutes of ambient exposure. As a proof-of-principle demonstration of pattern preservation, a H-passivated Si sample patterned and passivated with independent Cl, Br, I, and bare Si regions was shown to maintain its integrity in all but the bare Si region post-exposure to an N₂environment. The successful demonstration of the preservation of APAM patterns outside of UHV environments opens new possibilities for transporting atomically-precise devices outside of UHV for integrating with non-UHV processes, such as other chemistries and commercial semiconductor device processes.

Recurrent aplastic anemia with donor-type aplasia: A rare occurrence in the Indian subcontinent

Donor-type aplasia (DTA) is a condition where an individual continues to be aplastic even after a successful engraftment of a hematopoeitic stem cell transplant with a majority of donor type cells in the bone marrow. This entity has been seen with varying frequency around the world, especially in Southeast Asia. However, its incidence in the Indian subcontinent remains fairly low. Here is a case of a 17-year-old child with DTA who had a 89% population of donor cells after a successful transplant and presented with recurrent severe aplastic anemia later. The patient eventually succumbed to his condition before a second transplant could be performed. The awareness about the seriousness of this relatively rare condition, therefore, needs to be emphasized.

COVID-19 appropriate behavior in India: Time to invest for the benefits in future

The COVID-19 pandemic gave an opportunity to adopt many appropriate changes in the behavior of the people in India. The major gears of those behavior changes were the enforcement by the government, fear, motivation (self and induced), and self-experiences or realizations with time. If those changes are fitted in the Trans-Theoretical Model, Indian people have passed through the “Pre-Contemplation” to “Action” stage of behavior changes during different phases of this pandemic. Frequent hand hygiene, maintaining physical distancing, use of face mask, cough etiquettes, avoid greetings through physical contacts, fear in spitting and urination at public places, refrain from gatherings and avoiding outside food are some of the examples of those appropriate behaviors which were enforced or learnt during the COVID pandemic. The continuous lockdown made people understand the difference between “want” and “need,” the importance of local production, and the significance of social media and technology in routine life. The work-from-home strategy gave a chance to appreciate the work--life balance in a more applied way. The first-ever lifetime experience of unbelievable rejuvenating nature because of lack of human play taught people to appreciate nature. Although the current focus is on responding to the pandemic and on coping with its immediate effects, yet this is the time when there is an urgent need to create an enabling environment to support and sustain these COVID-19 appropriate behaviors (maintenance stage) to reap the maximum benefits out of them. Sustaining these appropriate behaviors is also important considering the bimodal distribution of the COVID-19 and possibility of advent of the second wave of COVID-19 in near future.

Stress degradation study of bortezomib: effect of co-solvent, isolation and characterization of degradation products by UHPLC-Q-TOF-MS/MS and NMR and evaluation of the toxicity of the degradation products

Bortezomib (BTZ) is a first-in-class, potent reversible inhibitor of proteasome used in the treatment of multiple myeloma, the second most common hematological cancer.

Of "Cotton Balls" and "Owl's eyes"

Report of a 3-month old girl child who died due to multi-systemic infection of cytomegalovirus (CMV) involving the lungs, liver and kidneys along with pneumocystis jiroveci pneumonia (PJP). The mother of the child tested positive for CMV IgG and HIV with a very low CD4 count (160/ μl). Co-infection of cytomegalovirus and pneumocystis jiroveci always occurs in the setting of immunocompromise. Congenital CMV infection is transmitted through the placenta, especially during the first trimester and causes severe multi-systemic disease whereas perinatal infection is acquired during childbirth/ breastfeeding where the babies have maternal protective antibodies leading to much milder or asymptomatic infection. PJP is more common in infancy and presents as hypoxic pneumonia. CMV causes cyto-nucleomegaly and classic "owl's eye" inclusions on histology while PJP presents with characteristic fluffy "cotton ball" alveolar exudates.

Fulminant amebic colitis: An unusual postoperative complication of intraabdominal malignancy

Amebiasis caused by protozoa Entamoeba histolytica (EH) is the third leading parasitic cause of human mortality. Although amebiasis is endemic in India, only about 10% of the infected individuals manifest disease. Clinical spectrum of amebiasis ranges from asymptomatic colonization to amebic colitis to hemorrhagic and fulminant colitis. Factors causing an invasive infection are not completely understood. Pathogen virulence, host immunity, and ability of the pathogen to evade host immune response play vital role in determining the disease course. Host factors such as immunocompromised states may make an individual susceptible to develop symptomatic infection. Malignancies usually result in chronic debilitation which may make the individual prone to develop invasive amebiasis with rapid progression. We report two cases of invasive amebiasis which developed a fulminant course in the immediate postoperative period after abdominal surgeries for visceral malignancies.

Prolonged persistence of SARS-CoV-2 in the upper respiratory tract of asymptomatic infected individuals

BACKGROUND

Duration of persistence of SARS-CoV-2 in the upper respiratory tract of infected individuals has important clinical and epidemiological implications.

AIM

We aimed to establish the duration and risk factors for persistence of SARS-CoV-2 in the upper respiratory tract of asymptomatic infected individuals.

METHODS

Data of repeat rRT-PCR (real-time reverse transcription-polymerase chain reaction) test done for SARS-CoV-2 infected individuals at our institute at Jodhpur, India were analysed from 19 March to 21 May 2020. Duration of virus persistence was estimated with parametric regression models based on weibull, log-normal, log-logistic, gamma and generalized gamma distributions. Factors associated with prolonged viral persistence were analysed with the best-fitting model.

RESULTS

Fifty-one SARS-CoV-2 infected individuals with repeat rRT-PCR test were identified with 44 asymptomatics. The asymptomatic individuals had median virus persistence duration of 8.87 days (95% CI: 7.65-10.27) and 95 percentile duration of 20.70 days (95% CI: 16.08-28.20). The overall median virus persistence including both symptomatic and asymptomatic individuals was found to be 9.18 days (95% CI: 8.04-10.48). Around one-fourth asymptomatics (10/44) demonstrated SARS-CoV-2 persistence beyond 2 weeks. Age <60 years and local transmission were found to be significantly associated with longer virus persistence among asymptomatic individuals on univariate regression but not in multivariate analysis.

CONCLUSION

Recommended home isolation duration for SARS-CoV-2 infected individuals in India should be extended from 17 days to at least 3 weeks. Prolonged persistence of SARS-CoV-2 in a considerable proportion of asymptomatic individuals merits attention with regard to ensuring universal infection prevention precautions irrespective of symptomatic status.

Nitrogen partitioning and remobilization in relation to leaf senescence, grain yield and protein concentration in Indian wheat cultivars

Nitrogen (N) fertilizer represents a significant cost for the grower and may also have environmental impacts through nitrate leaching and N₂O (a greenhouse gas) emissions associated with denitrification. The objectives of this study were to quantify the genetic variability in N partitioning and N remobilization in Indian spring wheat cultivars and identify traits for improved grain yield and grain protein content for application in breeding N-efficient cultivars. Twenty-eight bread wheat cultivars and two durum wheat cultivars were tested in field experiments in two years in Maharashtra, India. Growth analysis was conducted at anthesis and harvest to assess above-ground dry matter (DM) and dry matter and N partitioning. Flag-leaf photosynthesis rate (A _max ), flag-leaf senescence rate and canopy normalized difference vegetation index (NDVI) were also assessed. Significant N × genotype level interaction was observed for grain yield and N-use efficiency. There was a positive linear association between post-anthesis flag-leaf A _max and grain yield amongst the 30 genotypes under high N (HN) conditions. Flag-leaf A _max was positively associated with N uptake at anthesis (AGN_A). Under both HN and low N (LN) conditions, higher N uptake at anthesis was associated with delayed onset of flag-leaf senescence and higher grain yield. Under N limitation, there was a genetic negative correlation between grain yield and grain protein concentration. Deviation from this negative relationship (grain protein deviation or GPD) was related to genotypic differences in post-anthesis N uptake. It is concluded that N uptake at anthesis was an important determinant of flag-leaf photosynthesis rate and grain yield under high N conditions; while post-anthesis N uptake was an important determinant of GPD of wheat grown under low to moderate N conditions in India.

AB0006 HYPOMETHYLATION OF THE PROMOTER REGION OF TLR4 GENE AT A SYSTEMIC LEVEL IN PATIENTS WITH RHEUMATOID ARTHRITIS AND PERIODONTITIS

Background:

Periodontitis (PD) has long been linked with Rheumatoid arthritis (RA) [1]. Epigenetic modifications are being recently explored to explain such associations, DNA methylation being one such important mechanism.

Objectives:

To study the effect chronic generalized periodontitis on systemic methylation of TLR4 genes in comparison to only RA and RA with PD patients.

Methods:

Twenty-three RA patients, among which 11 patients had chronic generalized PD, 20 patients with only PD and 15 healthy individuals recruited. DNA was isolated from PBMCs of the participants blood, then were first bisulphite converted and then methylation specific PCR were performed using primers for methylated and um-methylated promoters of TLR4. The DNA amplifications were checked in horizontal gel electrophoresis. The methylation signatures were verified by DNA sequencing (Sanger) of the amplified products.

Results:

The anti-CCP, DAS-CRP and HAQ DI were higher in patients with both RA and PD (220±40, 5.7±0.2, 1.5±0.1 respectively, p<0.05). Control samples had shown amplification bands for methylated primers of TLR4 but not for un-methylated primers of TLR4. However, only RA, only PD and RA with PD samples, had shown amplification for un-methylated primers and not for methylated primers. These results together with DNA sequencing indicated that 4 CpG sites in the promoter ofTLR4 genes were hypo-methylated in the PBMCs of patients whereas those remain methylated in healthy individuals.

Conclusion:

The observations indicated that though PD is a localised disease of the gingiva there is a systemic involvement of TLR mediated pathways in them which is similar to those in RA. However, further validation in larger cohort and down-stream signalling molecules needs to be studied.

References:

[1]Ceccarelli F, Saccucci M, Di Carlo G, Lucchetti R, Pilloni A, Pranno N, Luzzi V, Valesini G, Polimeni A. Periodontitis and rheumatoid arthritis: the same inflammatory mediators?. Mediators of inflammation. 2019;2019.

Disclosure of Interests:

None declared

THU0009 SYSTEMIC DEREGULATION OF LONG NON-CODING RNAS IN PATIENTS WITH SYSTEMIC SCLEROSIS AND THEIR ASSOCIATION WITH REGULATORS OF FIBROSIS

Background:

Microvascular dysfunction is one of the major clinical challenges in systemic sclerosis (SSc) and mesenchymal transformation of the major event for micovascular dysfunction. Recent studies have shown epigenetic regulation of long non coding RNAs (lncRs) in different disease pathophysiology.

Objectives:

To study the differential expressions of lncRs in patients with SSc and to study their associations with regulatory molecules of fibrosis

Methods:

Peripheral Blood were collected from 15 diffused cutaneous SSc patients (dSSc) [ACR, 2013] and 10 age-sexes matched healthy controls. RNA was isolated from the peripheral blood & cDNAs were prepared and the Relative mRNA expressions were measured with respect to an endogenous control gene by real-time PCR. Protein expressions were measured by ELISA.

Results:

Increased expression of MEG3, MALAT1and NEAT1 (3.5, 3, 4fold respectively) has been found in SSc patients with respect to healthy individuals and they are mutually correlated (MEG3 and NEAT1:r=0.9, p<0.0001;MALAT1and NEAT1:r=0.7, p<0.0001;MEG3 and MALAT1r=0.7, p<0.0001). The expression of NEAT1 is significantly higher (p= 0.0009) in case patients with disease duration (DD) >5 years compare to the patients with DD≤5 years. No significant difference was found in the expression of MEG3 andMALAT1 between these two subpopulations. Modified Rodnan’s skin score (mRDss): the clinical parameter of measuring fibrosis, was significantly up regulated (p=0.004) in patients with long disease duration (>5 years) and also have a positive correlation with DD(r=0.2,p=0.2) and the regulatory RNAs: MEG3 (r=0.4,p=0.003), MALAT1 (r=0.2, p=0.2), and NEAT1(r=0.3, p=0.009).

The master regulator of fibrosis TGFβ which is significantly up regulated at both transcriptional (p<0.0001) and translational (p=0.0009) level has significant positive correlation with MEG3 (r=0.3, p=0.02), MALAT1 (r=0.5, p=0.0005), and NEAT1(r=0.3p=0.006).MEG3, MALAT1and NEAT1 also have significant high correlation (r=0.7,p<0.0001; r=0.6p<0.0001 andr=0.7p<0.0001 respectively) with αSMA: the marker of fibroblast activation and the collagen-I (r=0.3,p=0.03;r=0.3,p=0.03 andr=0.3p=0.03 respectively).

In multivariate analysisMEG3 and NEAT1 together could explain 37.5% variability of fibrotic marker and NEAT1 alone could explain 35.5% of the same.

Conclusion:

mRDSS probably does not reflect the underlying fibrotic process occurring sub-clinically, as no significant correlation was observed either with the disease duration or with the pro-fibrotic molecules (TGFβ, αSMA, and collagen1). The strong inter-correlation of NEAT1, MALAT1 and MEG3 suggest that any one of them might well be studied as specific marker of sub-clinical fibrosis.The long non coding RNAs (MALAT1, MEG3, NEAT1) better reflects the sub-clinical fibrosis occurring in the patients, suggested by strong correlation with fibrotic markers (TGFβ, αSMA, collagen1). The linear regression values suggest that NEAT1 could be an important biomolecule in SSc pathogenesis.

References:

[1]Asano Y, Sato S., Vasculopathy in scleroderma. Semin Immunopathol. 2015 Sep;37(5):489-500. doi: 10.1007/s00281-015-0505-5.

Disclosure of Interests:

None declared

Are newer insulin analogues better for people with Type 1 diabetes?

Achieving optimal blood glucose control in Type 1 diabetes is a delicate balance between ensuring tight glycaemic control and achieving this without the expense of hypoglycaemia and weight gain, two major factors impacting quality of life. This is a real challenge for people with Type 1 diabetes and underpins many of the struggles they face in self-managing on a day-to-day basis. The main goals of insulin delivery are to try to simulate the physiology of β-cell insulin secretion as closely as possible and to overcome the challenges of peripheral insulin administration by achieving rapidity of onset with mealtime insulins and stability of the glucose-lowering effects of long-acting insulins. Since the early days of human insulin use, there have been many developments in insulin formulations that aim to achieve these goals as much as possible, thus contributing to better glycaemic control whilst minimizing hypoglycaemia. In the present review we discuss the currently available insulin analogues and the challenges of achieving glucose control using current analogues in those on multiple daily injections, and appraise the evidence base for newer-generation insulin analogues, such as insulin degludec, glargine U300, faster-acting insulin aspart and BioChaperone lispro. We also highlight new insulins in development and unmet needs in people with Type 1 diabetes.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.

Synthesis, characterization and evaluation of 1-monoacylglycerols of unsaturated fatty acids as potential bioactive lipids

The synthesis of 1-monoacylglycerols of selected unsaturated fatty acids and their antimicrobial and cytotoxicity activity is reported in the present study. The monoacylglycerols of fatty acids like undecenoic, oleic, linoleic and erucic acids were prepared by chemical esterification with solketal followed by deprotection. Fatty acids like alpha linolenic, gamma linolenic and ricinoleic acids were initially isolated from natural sources and further enriched in their respective methyl ester forms. The monoacylglycerols of ricinoleic and linolenic acid methyl esters were prepared by enzymatic transesterification with solketal using lipase from Candida antarctica followed by deprotection. The synthesized 1-monoacylglycerols were purified and characterized by spectral studies. The antimicrobial activity revealed that the monoacylglycerol of gamma linolenic acid was the most effective antibacterial followed by the monoacylglycerols of undecenoic and alpha linolenic acids. In the cytotoxicity assay against five cell lines, all the monoacylglycerols exhibited moderate activity but the activity was best against MCF7 Human Breast Adenocarcinoma cell lines.