Structure and stability of different triplets involving artificial nucleobases: clues for the formation of semisynthetic triple helical DNA.

A triple helical DNA can control gene expression, help in homologous recombination, induce mutations to facilitate DNA repair mechanisms, suppress oncogene formations, etc. However, the structure and function of semisynthetic triple helical DNA are not known. To understand this, various triplets formed between eight artificial nucleobases (P, Z, J, V, B, S, X, and K) and four natural DNA bases (G, C, A, and T) are studied herein by employing a reliable density functional theoretic (DFT) method. Initially, the triple helix-forming artificial nucleobases interacted with the duplex DNA containing GC and AT base pairs, and subsequently, triple helix-forming natural bases (G and C) interacted with artificial duplex DNA containing PZ, JV, BS, and XK base pairs. Among the different triplets formed in the first category, the C-JV triplet is found to be the most stable with a binding energy of about - 31 kcal/mol. Similarly, among the second category of triplets, the Z-GC and V-GC triplets are the most stable. Interestingly, Z-GC and V-GC are found to be isoenergetic with a binding energy of about - 30 kcal/mol. The C-JV, and Z-GC or V-GC triplets are about 12-14 kcal/mol more stable than the JV and GC base pairs respectively. Microsolvation of these triplets in 5 explicit water molecules further enhanced their stability by 16-21 kcal/mol. These results along with the consecutive stacking of the C-JV triplet (C-JV/C-JV) data indicate that the synthetic nucleobases can form stable semisynthetic triple helical DNA. However, consideration of a full-length DNA containing one or more semisynthetic bases or base pairs is necessary to understand the formation of semisynthetic DNA in living cells.

Mechanistic insights on Bi-potentiodynamic control towards atomistic synthesis of electrocatalysts for hydrogen evolution reaction.

Herein, electrochemically assisted dissolution-deposition (EADD) is utilized over a three-electrode assembly to prepare an electrocatalyst for hydrogen evolution reaction (HER). Cyclic voltammetry is performed to yield atomistic loading of platinum (Pt) over SnS2 nanostructures via Pt dissolution from the counter electrode (CE). Astonishingly, the working electrode (WE) swept at 50 mV/s is found to compel Pt CE to experience 1000-3000 mV/s. The effect of different potential scan rates at the WE have provided insight into the change in Pt dissolution and its deposition behaviour over SnS2 in three electrode assembly. However, uncontrolled overpotentials at CE in a three-electrode assembly made Pt dissolution-deposition behavior complex. Here, for the first time, we have demonstrated bi-potentiodynamic control for dissolution deposition of Pt in four-electrode assembly over Nickel (Ni) foam. The dual cyclic voltammetry is applied to achieve better control and efficiency of the EADD process, engendering it as a pragmatically versatile and scalable synthesis technique.

Antifungal activity of novel azetidine tethered chitosan synthesized via multicomponent reaction approach.

The increasing incidences of fungal infections among Covid-19 infected patients is a global public concern and urgently demands novel antifungals. Biopolymers like chitosan hold unique structural properties and thus can be utilized in the synthesis of biologically important scaffolds. To address the current scenario, the author's synthesized novel chitosan-azetidine derivative by adopting one-pot multicomponent reaction approach. The influence of chemical modification on the structural characteristics was investigated by means of spectroscopic techniques viz. FT-IR and 1HNMR and elemental analysis. Additionally, the authors investigated the antifungal potential of chitosan-azetidine derivative against Aspergillus fumigatus 3007 and the results indicated higher antifungal effect with an antifungal inhibitory index of 26.19%. The SEM and confocal microscopy images also reflected a significant inhibitory effect on the morphology of fungal mycelia, thus reflecting the potential of synthesized chitosan-azetidine derivativeas a potential antifungal agent.

Complementary base pair interactions between different rare tautomers of the second-generation artificial genetic alphabets.

The functionality of a semisynthetic DNA in the biological environment will depend on the base pair nature of its complementary base pairs. To understand this, base pair interactions between complementary bases of recently proposed eight second-generation artificial nucleobases are studied herein by considering their rare tautomeric conformations and a dispersion-corrected density functional theoretic method. It is found that the binding energies of two hydrogen-bonded complementary base pairs are more negative than those of the three hydrogen-bonded base pairs. However, as the former base pairs are endothermic, the semisynthetic duplex DNA would involve the latter base pairs.

Incisional hernia rates following midline laparotomy in the obese patient: a retrospective review.

PURPOSE: Incisional hernia is the most common complication of midline laparotomy. Although obesity is a known risk factor, the incidence of hernia formation in obese patients is not well defined. We sought to define the rate of incisional hernia formation in obese patients undergoing primary midline laparotomy in a large academic medical center. METHODS: Obese patients (BMI ≥ 30 kg/m2) who underwent an elective or urgent primary midline laparotomy from 2017 to 2021 at our institution were retrospectively identified. A blinded hernia surgeon reviewed imaging to assess for incisional hernia formation, defined as a midline fascial defect with intra-abdominal contents herniated outside of the peritoneal cavity. RESULTS: A total of 2241 patients met inclusion criteria. Cross-sectional imaging was available for 914 (41%) of these patients. The median BMI for all patients was 34.3 kg/m2 (range 30.0-59.1). Median time to follow-up imaging was 316 days (181-957, IQR = 185) for all patients and 316 days (201-903, IQR = 184) for patients with incisional hernia. In total, 474 (51.9%) had radiographic evidence of an incisional hernia. Colorectal and General Surgery demonstrated the highest rate of incisional hernia (p < 0.001). During the study period, 138 patients (15.1%) underwent surgical repair of their hernia at our institution, with the highest percentage being Colorectal Surgery patients. CONCLUSION: There is a high rate of hernia formation and subsequent hernia repair in obese patients undergoing midline laparotomy. Most importantly, these findings demonstrate an immediate and pressing need to identify the patient risk factors and technical issues related to this rate of hernia formation.

Acute and sub-acute toxicity study of anti-obesity herbal granules in Sprague Dawley rats.

Toxicological studies are essential for developing novel medications in pharmaceutical industries including ayurvedic preparation. Hence, the present study is aimed to evaluate acute and 28-days repeated dose oral toxicity of anti-obesity polyherbal granules (PHG) in Sprague Dawley rats by OECD guidelines No 425 and 407, respectively. In an acute oral toxicity study, a single dose of 2 g/kg PHG was administered to rats and mortality, body weight, and clinical observations were noted for fourteen days. However, in the subacute oral toxicity study, the PHG was administered orally at doses of 0.3, 0.5 and 1 g/kg daily for 28 days to rats. Food intake and body weight were recorded weekly. On the 29th day, rats were sacrificed and subjected to haematological, biochemical, urine, necropsy, and histopathological analysis. In an acute oral toxicity study, no treatment-related, mortality, behavioral changes, and toxicity were found throughout fourteen days. Likewise, in the sub-acute toxicity study, no mortality and toxic effects were found in haematology, biochemical, urine, necropsy and histopathological analysis in rats for 28 days of treatment with PHG. Based on these results, the LD50 of PHG was found to be greater than 2 g/kg and the no-observed-adverse-effect level (NOAEL) of PHG for rats was found to be 0.5 g/kg/day. Thus, anti-obesity polyherbal granules showed a good safety profile in animal studies and can be considered an important agent for the clinical management of obesity.

Uterine kallikrein and arterial bradykinin activities and uterine arterial proliferation in response to acute estradiol-17ß exposure in ovariectomized ewes.

Estradiol-17ß (E2) increases kallikrein in rodent and human reproductive tissues. Kallikrein specific activity is increased in the porcine uterus when conceptus E2 is secreted at maternal recognition of pregnancy. When kallikrein acts on kininogen to liberate bradykinin, angiogenic and vasoactive factors are released. The uterus of ovariectomized ewes administered E2 undergoes rapid vascular changes via different patterns of angiogenic and vasoactive factors. Our hypothesis was that E2 would increase the specific activity and protein secretion of tissue kallikrein in endometrial explants culture media (ECM) and ewes exposed to E2 would have uterine arteries that would be more sensitive to the vasodilatory effects of bradykinin. Ovariectomized ewes received 100 mg of E2 implants for 0, 12, 24, or 48 h. After treatment, uterine weights were determined, and caruncles were processed for ECM. Uterine weights and uterine weight per ewe body weight were significantly greater in the 12 and 24 h ewes compared with the 0 h ewes, with the 48 h ewes being similar to the 24 h ewes. There were no statistically significant differences in caruncular tissue kallikrein protein secretion among the treatment groups. There was a tendency (P = 0.09) for duration of E2 exposure to influence tissue kallikrein specific activity where kallikrein activity was greater (P ≤ 0.05) in the 12 and 48 h ewes compared with the 0 h ewes, with 24 h ewes being intermediate (unprotected F test). Uterine arteries from ewes with E2 for 24 and 48 h had more sensitivity to bradykinin, via the bradykinin receptor 2, than uterine arteries from ewes with 0 or 12 h E2 exposure. We fail to reject our hypothesis as E2 did elicit a positive response in tissue kallikrein specific activity and bradykinin response. Further investigations are needed to determine how kallikrein and bradykinin may be involved in vascular remodeling of the ovine uterus.

Atypical presentations of cutaneous tuberculosis: Series of 10 cases.

Cutaneous tuberculosis classically presents as Lupus vulgaris, scrofuloderma, tuberculosis verrucose cutis and tubercular abscess. Hypersensitivity reaction to the bacilli leads to Lichen scrofulosorum and papulonecrotic tuberculids. At the same time, it can have myriad of clinical presentations, many of which are still undescribed. It is important to regularly update ourselves with these unusual manifestations so as to ensure early treatment and reduction of overall morbidity. In this case series tuberculosis manifesting as rapidly progressing diffuse facial granulomas, sporotrichoid tuberculosis, tuberculosis mimicking squamous cell carcinoma, scrofuloderma as tubercular ulcer, lupus vulgaris with nasal septal perforation, lupus vulgaris resembling furuncle, psoriasis, dermatitis and BT Hansen are described in immunocompetent individuals. These cases highlight the importance of recognition of atypical forms of cutaneous tuberculosis to minimize scarring and dissemination of bacilli.

Deep Transfer Learning Based Classification Model for COVID-19 Disease.

The COVID-19 infection is increasing at a rapid rate, with the availability of limited number of testing kits. Therefore, the development of COVID-19 testing kits is still an open area of research. Recently, many studies have shown that chest Computed Tomography (CT) images can be used for COVID-19 testing, as chest CT images show a bilateral change in COVID-19 infected patients. However, the classification of COVID-19 patients from chest CT images is not an easy task as predicting the bilateral change is defined as an ill-posed problem. Therefore, in this paper, a deep transfer learning technique is used to classify COVID-19 infected patients. Additionally, a top-2 smooth loss function with cost-sensitive attributes is also utilized to handle noisy and imbalanced COVID-19 dataset kind of problems. Experimental results reveal that the proposed deep transfer learning-based COVID-19 classification model provides efficient results as compared to the other supervised learning models.

A multiplex polymerase chain reaction for the simultaneous detection of the virus and satellite components associated with cotton leaf curl begomovirus disease complex.

Cotton leaf curl disease (CLCuD) is caused by a complex of several whiteflies (Bemisia tabaci Genn.)-transmitted begomovirus species, Cotton leaf curl Multan virus (CLCuMuV), Cotton leaf curl Kokhran virus (CLCuKoV) and Cotton leaf curl Alabad virus (CLCuAlV) by individual of mixed infection, associated with Cotton leaf curl Multan betasatellite (CLCuMB) and several alphasatellites. The disease causes major economic losses in cotton in the Indian subcontinent. For monitoring of epidemiology and development of management strategies of CLCuD, a quick, sensitive and effective method capable of detecting all the begomovirus, betasatellite and alphasatellite components associated with CLCuD is required. With this objective, a multiplex polymerase chain reaction (mPCR) assay was developed for the simultaneous detection of these three viral components associated with CLCuD of cotton. Primers for each component were designed based on the retrieved reference sequences from the GenBank. Each pair of primers, designed for each of the respective component, was evaluated for its sensitivity and specificity in both the component-specific simplex polymerase chain reaction (sPCR) and mPCR assay. This report identified three viral component-specific pairs of primers which, in all combinations, amplified simultaneously the CP gene (780 nts) of the begomovirus, the ßC1gene (375 nts) of the betasatellite and the Rep gene (452 nts) of the alphasatellite associated with CLCuD in the mPCR assays. The amplified products specific to each component produced by these assays were identified based on their amplicon sizes, and the identities of the viral components amplified were confirmed by cloning and sequencing the amplicons obtained in the mPCR. The mPCR assay was validated using naturally CLCuD-affected cotton plants of the fields. This assay will be useful for rapid detection of CLCuD-associated begomovirus, betasatellite and alphasatellite DNA in field samples, extensive resistance screening in resistance breeding programme, and also monitoring epidemiology for detection of virus and its components when symptoms are mild or absent in the plant.

Impact of Mesoporous Nano-Silica (SiO2) on Seed Germination and Seedling Growth of Wheat, Pea and Mustard Seed.

Wide range of nanomaterial applications is helpful to promote sustainable agriculture to the point of nanolevel. With regard to this, biocompatible silica nanoparticles have been used as a nanopriming agent for enhancing seed germination in rabi crops like wheat, pea and mustard. The current study was carried out in a completely randomized block design with four replications. One part of nanosilica (8 g/L) and three parts of Gibberellic acid (GA3) loaded nano-silica (100 ppm, 125 ppm and 150 ppm) were used for the experimental purpose. The result showed positive significant effect of nanopriming with nano-silica and GA3 loaded nano-silica on seed germination percentage, shoot and root length, seedling length, fresh weight, dry weight and vigour index-I and II at P ≤ 0.05. A comparative study on germination percentage for three of the cereal crops was done and calculated further. It was found to be higher as 91% in wheat, 91% in pea and 75% in mustard. This effect of nanopriming directly help in elevating the activity of α-amylase enzyme, resulting in higher concentration of soluble sugar content needed for supporting seed germination and growth of seedling. In this paper, the nanopriming-induced seed germination is proposed, including the creation of nanopores for enhanced water uptake, rebooting ROS/antioxidant systems in seeds, generation of hydroxyl radicals for cell wall loosening, and nano-catalyst to fasten starch hydrolysis.

Emission characteristics of ultrafine particles from bare and Al2O3 coated graphite for high temperature applications.

Owing to its exceptional properties at high temperature, graphite is used in several applications such as structural material and fuel block in high temperature nuclear reactors. Air ingress is one of the serious safety concerns in these reactors. Oxidation of graphite leading to increased porosity affects its mechanical strength and may lead to core collapse resulting in a severe accident. During such a scenario, generation of graphite particles could be the main hazard. Once generated, these particles often in fine and ultrafine sizes, may carry radioactivity to large distances and/or for long times. These particles owing to their higher surface to volume ratio possess an additional inhalation hazard. Ultrafine particles have the potential to enter into respiratory tract and cause damage to body organs. Coating of graphite components is preferred to reduce the oxidation induced damages at high temperatures. In the present work, effect of alumina (Al2O3) coating on the emission characteristics of particles from graphite under high temperature conditions has been investigated. Bare and Al2O3 coated graphite specimens were heated within a closed chamber at varying temperatures during these experiments. Temporal evolution of concentrations of gases (CO and CO2) and particles were measured. The results reveal that Al2O3 coating on the graphite delayed the oxidation behavior and the structure of graphite remained largely intact at high temperatures. A significant reduction in aerosol formation and CO emission was also noticed for the coated specimens.

A Noncytotoxic Temporin L Analogue with In Vivo Antibacterial and Antiendotoxin Activities and a Nonmembrane-Lytic Mode of Action.

Cytotoxic frog antimicrobial peptide Temporin L (TempL) is an attractive molecule for the design of lead antimicrobial agents due to its short size and versatile biological activities. However, noncytotoxic TempL variants with desirable biological activities have rarely been reported. TempL analogue Q3K,TempL is water-soluble and possesses a significant antiendotoxin property along with comparable cytotoxicity to TempL. A phenylalanine residue, located at the hydrophobic face of Q3K,TempL and the "d" position of its phenylalanine zipper sequence, was replaced with a cationic lysine residue. This analogue, Q3K,F8K,TempL, showed reduced hydrophobic moment and was noncytotoxic with lower antimicrobial activity. Interestingly, swapping between tryptophan at the fourth and serine at the sixth positions turned Q3K,F8K,TempL totally amphipathic as reflected by its helical wheel projection with clusters of hydrophobic and hydrophilic residues and the highest hydrophobic moment among these peptides. Surprisingly, this analogue, SW,Q3K,F8K,TempL, was as noncytotoxic as Q3K,F8K,TempL but showed augmented antimicrobial and antiendotoxin properties, comparable to that of TempL and Q3K,TempL. SW,Q3K,F8K,TempL exhibited appreciable survival of mice against P. aeruginosa infection and a lipopolysaccharide (LPS) challenge. Unlike TempL and Q3K,TempL, SW,Q3K,F8K,TempL adopted an unordered secondary structure in bacterial membrane mimetic lipid vesicles and did not permeabilize them or depolarize the bacterial membrane. Overall, the results demonstrate the design of a nontoxic TempL analogue that possesses clusters of hydrophobic and hydrophilic residues with impaired secondary structure and shows a nonmembrane-lytic mechanism and in vivo antiendotoxin and antimicrobial activities. This paradigm of design of antimicrobial peptide with clusters of hydrophobic and hydrophilic residues and high hydrophobic moment but low secondary structure could be attempted further.

A systematic review of automated feeder detection software for locoregional treatment of hepatic tumors.

PURPOSE: The purpose of this study was to perform a systematic review of current literature describing the efficacy and technical outcomes of transarterial liver therapies using automated feeder detection (AFD) software. MATERIALS AND METHODS: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. A structured search was performed in the PubMed, SCOPUS, and Embase databases of patients undergoing locoregional therapy of liver tumors utilizing AFD software. Demographic data, procedure data (including radiometrics) and tumor response rate were recorded. Where available, performance of AFD was compared to conventional digital subtraction angiography (DSA) and cone-beam CT (CBCT) without AFD. RESULTS: A total of 14 full-text manuscripts met inclusion criteria, comprising 1042 tumors in 604 patients (305 men, 156 women; mean age, 68.6±6.0 [SD] years), including 537 patients with hepatocellular carcinoma, 8 with metastases from neuroendocrine tumors, and 59 patients without reported etiology. Reported sensitivity of AFD ranged between 86% and 98.5%, compared to DSA alone (38% - 64%) or DSA in combination with CBCT (69% - 81%). Three studies reported tumor response by modified response evaluation criteria in solid tumors (mRECIST) guidelines, with complete response in the range of 60% - 69%. CONCLUSION: AFD is a promising new technology for the identification of intrahepatic and extrahepatic tumor-feeding arteries and should be considered a useful adjunct to conventional DSA and CBCT in the treatment of liver tumors.

Carbohydrate hitched imidazoles as agents for the disruption of fungal cell membrane.

The fungal diseases represent an increasing global health burden and have transformed from a rare curiosity to the leading cause of human mortality. The present manuscript reports the antifungal potential of two novel compounds possessing a carbohydrate and an imidazole moiety. Antifungal susceptibility test determined the growth inhibition potential of the synthesized compounds against Aspergillus niger 9689 and it was observed that compounds D and E gave an antifungal inhibitory index of 66.66 and 56.67% respectively. Further, ultra-structure analysis of the treated fungal mycelia through scanning electron microscope (SEM) and confocal microscopy indicated significant membrane permeability and disintegration of fungal cell membrane, thus highlighting the probable role of the synthesized compounds as inhibitors of fungal lanosterol 14α-demethylase. In silico studies corroborated with the in-vitro results, as the synthesized compounds interacted with the critical amino acids present at the active site of the fungal enzyme (lanosterol 14α-demethylase).

A novel monoclonal antibody against enolase antigen of Aspergillus fumigatus protects experimental aspergillosis in mice.

Aspergillus fumigatus is one of the most common opportunistic fungal pathogens responsible for a variety of diseases in human, from allergic bronchopulmonary aspergillosis to chronic pulmonary aspergillosis, mostly in immunocompromized patients. In this study, one monoclonal antibody MAb R-5 (IgM) raised against enolase cell surface protein of A. fumigatus exhibited significant inhibition of spore germination in A. fumigatus (88.3%), Aspergillus flavus (57.4%) and Aspergillus niger (30.6%). The MAb R-5 also showed in vitro fungicidal activity against these species as follows: A. fumigatus (24.1%), A. flavus (13.3%) and A. niger (8.8%). These findings were supported by the indirect immunofluorescence microscopy, where the antibody showed binding with germinated spores and hyphae of A. fumigatus as well as A. flavus and A. niger.In vivo protective effect of MAb R-5 was evaluated in BALB/c mice challenged intravenously with A. fumigatus spores, where a significant reduction in CFU (85.9%) was observed in kidney tissue. The mean survival time of mice treated with MAb R-5 (18.5 days) was also enhanced compared to control (6.5 days). These results indicate that MAb R-5 could be valuable in diagnosis as well as in the treatment of broad range of Aspergillus infections.

Factors Influencing Mating Behavior and Success in the Red Palm Weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae).

The effects of body size, age, feeding and mating status, conspecific volatiles from live adults, synthetic aggregation pheromone, and a pheromone synergist, ethyl acetate, on the mating behavior of red palm weevil, Rhynchophorus ferrugineus Olivier, were investigated. To evaluate these factors, variables such as mating latency, frequency and duration, and refractory period were assessed. While both, body size and age, influenced the mating behavior, the latter showed a stronger effect. The large males recorded frequent and longer matings, whereas the young males outperformed the old weevils in all the studied variables. The difference in body size or age of females showed a limited effect. After 72 h without food, the males showed a significant decline in mating frequency and duration, and refractory period. Mating status showed comparatively stronger effects on mating variables. In the case of females, mating status emerged as the most important factor affecting four out of five variables. The volatiles from the males, grouped males and females, and synthetic aggregation pheromone both alone and in combination with ethyl acetate triggered mating initiation, propelled mating frequency, prolonged total mating duration, and reduced the refractory period. However, the presence of females or ethyl acetate alone was a weak mating stimulator.

Response Surface Methodology-Genetic Algorithm Based Medium Optimization, Purification, and Characterization of Cholesterol Oxidase from Streptomyces rimosus.

The applicability of the statistical tools coupled with artificial intelligence techniques was tested to optimize the critical medium components for the production of extracellular cholesterol oxidase (COD; an enzyme of commercial interest) from Streptomyces rimosus MTCC 10792. The initial medium component screening was performed using Placket-Burman design with yeast extract, dextrose, starch and ammonium carbonate as significant factors. Response surface methodology (RSM) was attempted to develop a statistical model with a significant coefficient of determination (R2 = 0.89847), followed by model optimization using Genetic Algorithm (GA). RSM-GA based optimization approach predicted that the combination of yeast extract, dextrose, starch and ammonium carbonate at concentrations 0.99, 0.8, 0.1, and 0.05 g/100 ml respectively, has resulted in 3.6 folds increase in COD production (5.41 U/ml) in comparison with the un-optimized medium (1.5 U/ml). COD was purified 10.34 folds having specific activity of 12.37 U/mg with molecular mass of 54 kDa. The enzyme was stable at pH 7.0 and 40 °C temperature. The apparent Michaelis constant (Km) and Vmax values of COD were 0.043 mM and 2.21 µmol/min/mg, respectively. This is the first communication reporting RSM-GA based medium optimization, purification and characterization of COD by S. rimosus isolated from the forest soil of eastern India.

Does 8-Nitroguanine Form 8-Oxoguanine? An Insight from Its Reaction with •OH Radical.

8-Nitroguanine (8-nitroG) formed due to nitration of guanine base of DNA plays an important role in mutagenesis and carcinogenesis. In the present contribution, state-of-the-art quantum chemical calculations using M06-2X density functional and domain-based local pair natural orbital-coupled cluster theory with single, double, and perturbative triple excitations (DLPNO-CCSD(T)) methods have been carried out to investigate the mechanism of reaction of •OH radical with 8-nitroG leading to the formation of 8-oxoguanine (8-oxoG) (one of the most mutagenic and carcinogenic derivatives of guanine) in gas phase and aqueous media. Calculations of barrier energies and rate constants involved in the addition reactions of •OH radical at different sites of 8-nitroguanine show that C8 and C2 sites are the most and least reactive sites, respectively. Relative stability and Boltzmann populations of adducts show that the adduct formed at the C8 site occurs predominantly in equilibrium. Our calculations reveal that 8-nitroG is very reactive toward •OH radical and is converted readily into 8-oxoG when attacked by •OH radicals, in agreement with available experimental observations.