Switching the Moiré Lattice Models in the Twisted Bilayer WSe2 by Strain or Pressure.

Moiré superlattices of twisted van der Waals heterostructures provide a promising and tunable platform for simulating correlated two-dimensional physical models. In twisted bilayer transition-metal dichalcogenides with twist angles close to 0°, the Γ and K valley moiré bands are described by the honeycomb and the triangular effective lattice models, respectively, with distinct physics. Using large-scale first-principles calculations, we show that in-plane biaxial strain and out-of-plane pressure provide effective knobs for switching the moiré lattice models that emerged at the band edges in twisted bilayer WSe2 by shifting the energy positions of the Γ and K valley minibands. The shifting mechanism originates from the differences in the orbital characters of the Γ and K valley states and their responses to strain and pressure. The critical strain and pressure for switching the Γ/K valleys are 2.11% and 2.175 GPa, respectively.

Survival and success of composite resin restorations in endodontically treated maxillary incisors with minimal structure loss.

The primary aim of this study was to evaluate the clinical performance of nanofilled composite resin restorations in traumatized, endodontically treated maxillary incisors with structural loss of 40% or less. The performance of the restorations was assessed in terms of longevity (survival) and esthetics (success) over a 20-month period. The secondary objective was to employ a novel digital method to quantify preoperative tooth structure loss. Sixty-one fractured maxillary incisors in 55 patients were included in the study. The teeth were photographed with a digital single-lens reflex camera equipped with a macro ring flash. The amount of lost tooth structure was calculated with digital photography software. The teeth were restored with a nanohybrid composite resin and self-etching adhesive system bonding agent. To assess esthetics, color change in the blue-yellow axis (Δb*) of the composite resin restoration was evaluated digitally with the Commission Internationale de l'Eclairage (CIE) L*a*b color system. The Wilcoxon signed-rank test was used to assess Δb*, and a Kaplan-Meier survival analysis was used to assess the longevity of the restorations. The study findings showed a statistically significant difference between pretreatment and posttreatment b* values (P < 0.05), but the difference was too small to be clinically perceptible to the human eye. A total of 5 restorations (9.8%) failed. The remaining restorations survived for a mean (SD) period of 18.6 (4.4) months. The log-rank test did not show any significant association between the amount of residual tooth structure and success of the restoration. The results of this study showed that use of direct composite resin restorations in endodontically treated maxillary incisors resulted in acceptable survival and success rates. Trial registration: Clinical Trial Registry of India No. CTRI/2020/01/023019.

Noscapine hydrochloride (benzyl-isoquinoline alkaloid) effectively prevents protein denaturation through reduction of IL-6, NF-kB, COX-2, Prostaglandin-E2 in rheumatic rats.

Noscapine hydrochloride (benzyl-isoquinoline antitussive alkaloid) is an opium derivative and generally used as a cough suppressant. Numerous studies on noscapine hydrochloride have reported that it has potent anti-inflammatory activity. However, the mechanisms by which it exerts an anti-inflammatory function is not well understood. Protein denaturation is the primary step that leads to the organ destruction and permanent arthritic disability. The above-mentioned facts provided the ground to plan this study using different in-vitro and in-vivo approaches. RT-qPCR and ELISA assays were used to assess the inflammatory markers related to protein denaturation in complete adjuvant persuaded rheumatism in Sprague - Dawley rats. The results were collected as paw volume and body weight changes, arthritic scoring and serum antioxidant enzymes assays. These findings demonstrated that all doses of noscapine hydrochloride (10, 20 and 40 mg/kg) studied in this study, significantly (p < 0.001) decreased the protein denaturation by preventing the increase in levels of interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nuclear factor-kB (NF-kB), cyclooxygenase-2 (COX-2) and prostaglandin E2. Noscapine hydrochloride significantly reduced the paw volume (p < 0.001), arthritic scoring and reversed the body mass as compared to arthritic control diseased rats.

Phytochemical investigation and pharmacological evaluation of methanolic flower extract of Saussurea heteromalla.

Saussurea heteromalla is the one of specie of Saussurea plant belonging to family Asteraceae. The Saussurea heteromalla found extensively in Pakistan. The literature review highlights numerous biological aspects of Saussurea heteromalla. This research therefore aims to assess its potential anti-inflammatory, antioxidant, anti-cancer. Carrageenan induced rat paw edema model was used for the evaluation of anti-inflammatory activity. DPPH method was used to evaluate anti-oxidant activity. The MTT (3- [4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide) test was used to assess the viability of the cells for the assessment of the cytotoxic effect of the extract. Methanolic Saussurea heteromalla flowers extract analysis carried by GC-MS, result 19 different peaks. The methanolic extract of Saussurea heteromalla at 400mg/kg dose have equal anti-inflammatory action when compare with standard that is diclofenac sodium. Anti-oxidant activity of methanolic extract is also very good. IC50 value of methanol extract was 25µg/ml. 18.72% cell survive out of 100 when methanolic flower extract of Saussurea heteromalla was given at the dose of 400mg, which shows the cytotoxic effect. This activity shows that plant Saussurea heteromalla methanolic flowers extract have anti-inflammatory, anti-oxidant, cytotoxic effect. The isolation and characterization-based investigations proclaiming the biologically leading active molecule are worthy for further study in this regard.

Horner syndrome-A rare complication after thyroidectomy for benign thyroid swelling.

Horner syndrome occurring after thyroidectomy is a rare entity and most of the reported cases have happened after surgeries on malignant thyroid swellings. In the present report, we describe a 27-year-old female who developed ptosis, miosis, enophthalmos, and anhidrosis on the second post-operative day after thyroidectomy for benign goiter. Post-operative ultrasound, computed tomography of neck, nerve conduction study, and electromyography of brachial plexus were unremarkable. Patient was kept on conservative management. She was given short course of Prednisolone orally for 2 weeks and was discharged on 150 mcg thyroxine. She had significant improvement in ptosis, miosis, and enophthalmos after six months. Horner syndrome is a rare but an important complication after thyroidectomy which may lead to cosmetic disfigurement. Surgeons should be well aware of this possibility and its presentation for timely recognition and management postoperatively. Early intervention should be done for any reversible cause, i.e., hematoma and oral steroids should be initiated as early as possible.

Electron number density conservation model combined with a self-absorption correction methodology for analysis of nanostructure plasma using laser-induced breakdown spectroscopy.

We studied laser ablation and plasma property evolution for a nickel (Ni) doped tin (Sn) oxide nanostructures target using laser-induced breakdown spectroscopy (LIBS). The transition metal Ni doped tin oxide nanostructures were synthesized by co-precipitation and hydrothermal methodologies. The size of prepared nanoparticles was verified by X-ray diffraction and transmission electron microscopy techniques. A frequency-doubled pulsed Nd:YAG laser with a wavelength of 532 nm was used to produce ablated plasma nanostructures. Ablation of doped and undoped nanostructures revealed salient-enhanced spectral emissions compared with their bulky counterparts. The emission lines of the constituent elements of doped material were used to find plasma parameters. The plasma temperature was estimated from a Boltzmann plot, and the electron number density was determined from the Saha-Boltzmann equation. The self-absorption effect has been observed in tiny plasma of nanostructures. The affected profiles of spectral lines of Ni and Sn nanoparticles due to self-absorption in LIBS spectra were corrected by the internal reference self-absorption correction (IRSAC) methodology. After correction of emitted line intensities by IRSAC, the electron number density (END) conservation approach was applied for quantitative analysis of doped nanostructures. In the END conservation approach, quantitative analysis of samples was carried out using electron number densities. Quantitative results derived from the END conservation approach at high and low concentrations exhibited good correlation when these were compared and validated with results from a conventional calibration free approach and the standard recognized energy dispersive X-ray technique.

Untapped renewable energy potential of crop residues in Pakistan: Challenges and future directions.

Sustainability in power generation mainly depends on the transition from fossils to sustainable energy resources. Biomass from the crop residue has huge potential for renewable power generation, but it is still not utilized to its full potential. This study presents a comprehensive methodology to evaluate and forecast the current and future availability of selective crop residue to generate renewable energy. A forecast model incorporating historical trends in the crop yield has been developed in MATLAB and implemented for crop residue based biomass resource assessment of five primary crops (wheat straw, rice husk, rice straw, cotton straw, corn stover, and bagasse) in order to estimate the energy generation potential for Pakistan from 2018 till 2035. It was found that about 40 million tonnes of crop residue was available in Pakistan for power generation in the year 2018 considering a residue removal (availability) factor of 50%. This translates to an estimated potential of about 11,000 MW of electricity generation capacity using crop residue derived biomass for 2018. This capacity is predicted to gradually increase up to 16,000 MW by the year 2035 based on the trends in the growth of crop production since 2001. The suitability of a potential region for the installation of 100 MW biomass-fired power plants was also assessed by calculating crop residue density and an equivalent collection radius (Re) of 50 km (km). Punjab province of Pakistan, being an agricultural province, with relatively better road infrastructure can sustain crop residue based power plants of up to 7000 MW cumulative capacity at various locations. The challenges, such as economic, logistics, regulatory and political barriers, in generating renewable energy from biomass along with their potential solutions were also discussed. The study also provides a baseline for future research to evaluate and forecast the growth in bio-power generation potential of any biomass resource in a region based on crop yield and area of the region.

CO2 capture through electro-conductive adsorbent using physical adsorption system for sustainable development.

The most critical energy and environmental challenge that our planet is facing today is to minimize the dependence on fossil fuels. Carbon dioxide may be of utmost significance as a solution of this issue through realization of carbon neutral energy cycle. Potentially, this could be achieved through the carbon dioxide capture as the urgent response to ongoing climate change. Activated carbon (AC) adsorption is one the most effective, environment friendly and techno-economic process for the carbon capture. In the current research, an electro-conductive-activated carbon was prepared by mixing powdered activated carbon (PAC) with an electro-conductive polymer (ECP). Different ratios of 0, 25, 50, 75 and 100 wt% of ECP with PAC were used for the different analyses of activated carbons in a gas mixture of CO2/N2 using a physical adsorption system. Adsorption and desorption analyses, capacities of the process and desorption effects were examined. Electro-conductive polymers (ECP) were mixed with AC samples, where breakthrough time was increased up to 400% when mixed with the PAC for CO2 adsorption. Following adsorption analysis, desorption of activated carbons was conducted with different potentials. It was revealed that mixing could help the PAC sample to overcome the packing issue to increase the breakthrough capacity and the volumes before and after the breakthrough adsorption in the packed bed systems. The desorption rates of the PAC sample were also enhanced, and fast desorption was observed when mixed with ECP. It is envisioned that this method is very much promising carbon capture method for the techno-economic feasibility and sustainable development of the environment.

Adsorptive Separation of Benzene, Cyclohexene, and Cyclohexane by Amorphous Nonporous Amide Naphthotube Solids.

Benzene hydrogenation is an important industrial process. The reaction is incomplete, resulting in a mixture of benzene, cyclohexane, and/or cyclohexene that have to be separated before any further reactions. The currently used extractive and azeotropic distillations are operationally complex and energy intensive. Adsorptive separation provides an alternative energy-efficient method. However, the separation of the ternary mixture by adsorptive separation has not yet been reported. In the present research, we report two macrocyclic hosts with hydrogen-bonding sites in their cavities that are able to separate the ternary mixture of benzene, cyclohexene, and cyclohexane. N-H⋅⋅⋅π interactions were found to play a key role in the selective separation. In addition, fast adsorption, high loading ratios, and easy recycling are achieved with the present system, which is promising for practical applications.

Ignition sensitivity of different compositional wood pellets and particle size dependence.

Partial or complete substitution of coal with renewable biomass like wood is a sustainable and effective solution to reduce the CO2 emissions in the atmosphere. Utilization of these woods in the form of compact pellets facilitates in its handling and transportation with higher energy density. However, for electric power generation the pellets are broken up into their constituent milled finer particles for burning as a pulverised biomass flame. There is a dust fire/explosibility hazards in the process handling facilities such as in storage, conveying and milling. In the present work, four commercial pellets were investigated, and each pellet sample was split into three size ranges <63 µm, 63-500 µm and <500 µm. The flame propagation characteristics and their lean flammability limit for each pulverised pellet was determined using modified Hartmann dust explosion tube. It was found that the fine particles, with lower lean flammability limits of 0.3-0.7 equivalence ratio, intensify the explosibility risk (dP/dt of 10-15 bar/s for most reactive concentration) of the dust due to fast volatile release rate. Comparison was also made between particle size distribution (PSD) of the finer fractions (<63 µm) of wood samples in comparison to crop residue samples that showed 70-80% larger size distribution for wood samples due to elongated particles as showed by Scanning Electron Microscope (SEM). Results showed that the ash + moisture content had a stronger effect on wood samples than on agricultural residue's samples. The results showed that the explosibility characteristics of the pellets industry's feed-stocks was variable and dependent on the pellet composition and this needs to be taken into account in explosion protection and in utilising the pellets in the main pulverised biomass combustion.

Bias-dependent transport properties of passivated tilted black phosphorene nanoribbons.

Using the density functional theory incorporated with a non-equilibrium Green's function (NEGF) technique, we explored the bias-dependent transport of tilted phosphorene nanoribbons. Herein, we considered three types of nanoribbons: self-passivated (TPNRself), H-passivated (TPNRH), and O-passivated (TPNRO) systems. The TPNRself showed an indirect band gap of 0.53 eV, whereas the TPNRH displayed a direct band gap of 1.32 eV. In TPNRO, we observed a spin-polarized band structure with a spin-dependent band gap. We found that the bias-dependent I-V curve was dependent on the passivation effect. In TPNRself and TPNRH, the current monotonically increased with an external bias, but the magnitude of the current in TPNRself was more than 10 times than that in TPNRself. Unlike the I-V characteristics in TPNRself and TPNRH, the current in TPNRO almost vanished beyond an external bias of 1.7 V. Mostly, the bias-dependent I-V was interpreted based on the band structure in the lead parts. However, we found that this conventional approach was not sufficient to analyze the I-V curve. Indeed, we showed that the detailed I-V curve could be understood by calculating the bias-dependent density of states in the scattering part related to the transmission channel. It was also found that the electron flow channel was dependent on the passivation effect and uniformly distributed over the entire nanoribbon in TPNRself and TPNRH. In contrast, the electron flowed mostly along the edge line in TPNRO. Moreover, we have found that spin polarization in the conduction current can be manipulated by an external bias, and this may suggest that the TPNRO can be utilized for potential spintronic applications.

Genetic barcoding and phylogenetic analysis of dusky cotton bug (Oxycarenus hyalinipennis) using mitochondrial cytochrome c oxidase I gene.

Cotton dusky bug (Oxycarenus spp.) mostly attack on cash crops such as Gossypium, Cola and Hibiscus which affect the national economy therefore sustainable pest management is needed. Cytochrome c oxidase I (COI) gene is utilized as marker gene for DNA barcoding, genetic and ecological study of insects. In present study insect (cotton dusky bug) samples were collected from cotton fields in Faisalabad. COI gene was amplified from genomic DNA of bug and cloned into pTZ57R/T vector (Fermentas). The clone was sent to Macrogen (South Korea) for Sanger sequencing. The phylogenetic analysis and pairwise multiple sequence alignment showed that our cotton dusky bug grouped with two species of Oxycarenus genus and highest sequence identity was 91.1% with Oxycarenus hylinipennis. This is the first report of genetic barcode of Oxycarenus hylinipennis from cotton from Pakistan.

Hydrogen functionalization induced two-dimensional ferromagnetic semiconductor in Mn di-halide systems.

We explored the electronic and magnetic properties of two-dimensional manganese di-halides (MnY2, Y = I, Br, Cl) and hydrogenated systems (MnHY2). The pristine MnY2 monolayers had a very weak magnetic exchange interaction and we found degenerated magnetic states between ferromagnetic and antiferromagnetic states although the Mn had a high magnetic moment of 5 µB with a finite band gap. However, we found that the electronic band structure and magnetic properties could be significantly altered by functionalization with hydrogen atoms because the degeneracy in the pristine MnY2 structure was broken and the FM ground state was obtained in all MnHY2 systems. We obtained a negative spin polarization in the H atom and the magnetic moment of the Mn atom decreased from 5 µB to 4 µB. However, this negative polarization played a pivotal role in inducing a FM ground state in the MnHY2 systems. Furthermore, the asymmetric spin dependent bang gap in MnHY2 was also greatly enhanced due to this hydrogenation as compared with that in the pristine MnY2 systems. This finding suggests that the hydrogenated MnHY2 can be used as a potential ferromagnetic semiconductor for spintronics.

Detection of interleukins-6 and 8 in saliva as potential biomarkers of oral pre-malignant lesion and oral carcinoma: A breakthrough in salivary diagnostics in Pakistan.

Oral cancer is at rise in our population due to increasing use of areca nut (Betel nut) with or without tobacco. It is the second frequent malignant tumour for both the gender in Pakistan. This non-interventional case control study was carried out with the aim to explore saliva as diagnostic medium for detecting interleukins (IL) 6 and 8 as biomarkers of pre-malignant lesions (PML) and oral carcinoma. Total 105 subjects were recruited and were divided into three groups "A", "B" and "C" each comprising of 35 subjects. Group "A" comprised of cases with strong clinical evidence of oral PML. Group "B" constitute clinical and histologically proven OSCC and group "C" include disease free subjects as controls. Saliva from all the recruited subjects was procured by drooling method and stored at-200C before further process. All the collected samples were centrifuged at 4500 rpm for 15 minutes at 4oC. Supernatant fluid was used in ELISA for detection and quantification of IL-6 & IL-8. Data was analysed by using Chi-square test and multivariate analysis was done by non-parametric test. P-value of 0.05 was taken as standard reference. Significant co-relation was found for qualitative salivary detection of IL-6 and IL-8 among the groups (P<0.001 and <0.0001 respectively). Regarding quantitative salivary concentration of leukotrienes, no significant co-relation was found in levels of IL-6 among the groups while there was significant association of IL-8 levels between the groups (P<0.0001).On post Hoc multiple comparison, significant co-relation was found among oral PML group and controls (P=0.001) and OSCC group and control (P=<0.0001). In conclusion salivary detection of IL-6 & IL-8 could be used as probable biomarker for early detection of oral PML & OSCC in etiologically distinct population of Pakistan.

Pathogenesis and Management of Alcoholic Liver Disease.

Alcoholic liver disease (ALD) is a leading cause of liver-related morbidity and mortality. ALD encompasses a spectrum of disorders ranging from asymptomatic steatosis, alcoholic steatohepatitis, fibrosis, cirrhosis and its related complications. Moreover, patients can develop an acute-on-chronic form of liver failure called alcoholic hepatitis (AH). Most patients are diagnosed at advanced stages of the disease with higher rates of complications and mortality. The mainstream of therapy of ALD patients, regardless of the disease stage, is prolonged alcohol abstinence. The current therapeutic regimens for AH (i.e. prednisolone) have limited efficacy and targeted therapies are urgently needed. The development of such therapies requires translational studies in human samples and suitable animal models that reproduce clinical and histological features of AH. In recent years, new animal models that simulate some of the features of human AH have been developed, and translational studies using human samples have identified potential pathogenic factors and histological parameters that predict survival. In this review, we discuss the pathogenesis and management of ALD, focusing on AH, its current therapies and potential treatment targets.

Assessing Attitudes and Perceptions of Obstructive Pulmonary Disease Patients towards Inhaler Therapy in a Low Income Country: A Cross Sectional Study.

Chronic respiratory diseases (CRD) like asthma and chronic obstructive pulmonary disease (COPD) are one of the leading causes of morbidity and mortality worldwide. A patient's perception, about his or her medicine, may have an impact on adherence to medications. The purpose was to assess the attitudes and perceptions, regarding inhaler therapy use, among patients with obstructive pulmonary disease in Pakistan, a developing country. With a questionnaire developing this cross-sectional study was conducted at the Department of Medicine's outpatient clinic at Civil Hospital, Karachi from October 2013 to January 2014. We used SPSS version 19 for data entry. The number of patients included in the study was 202. Fifty eight percent (58%) of the patients concurred that they were not compliant with the usage of inhalers and frequently missed their doses. Thirty three percent (33%) patients had the misconception that inhalers are prescribed for severe diseases only. Almost forty percent (40%) patients said that they would prefer oral medicines over inhalers for the management of their lung diseases. Sixteen percent (16%) of the patients had problems using their inhalers. Twenty six percent (26%) of the patients believed that inhalers have side effects. Thirty eight percent (38%) of the patients believed inhalers are addictive. Misconceptions regarding inhalers and its usage in asthma and COPD patients are common in Pakistan. These misconceptions not only lead to poor compliance with medications prescribed but also to frequent visits to hospitals. There is a need to educate patients in the country regarding inhalers in order to improve not only their symptoms, but also to improve their quality of life.

Obesity with irregular menstrual cycle in young girls.

Obesity is one of the leading causes of morbidity and mortality worldwide. Obese women are at increased risk of developing Type 2 Diabetes, cardiovascular diseases, hyperlipidemia, rectal carcinoma and gynecological problems including sub fertility, menstrual dysfunction and polycystic ovarian disease. The aim of this study was to assess relationship of obesity with menstrual irregularity in young girls that can help to create awareness among young girls about obesity and how it can affect fertility. It was a case controlled cross sectional study comprising of 220 participants from different colleges and universities of Karachi and from outpatients department of private clinic and Civil Hospital Karachi. A questionnaire was designed to assess the relationship of obesity with irregular menstrual cycle. Questionnaires were filled by co-authors after taking verbal consent. Data was collected from March 2013 to December 2013 and entered and analyzed on SPSS 16.0. Out of 220 participants obese and overweight were 67(30.4%) and 49(22.2%) respectively. Significant association was found between body composition and menstrual cycle irregularity as menstrual irregularity was present in only 9.5% when the BMI was normal and 14.09% and 24% girls in the overweight and obese categories respectively. Waist to hip ratio was found increased in 61.36% of girls. Sixty four point forty four percent (64.44%) of the girls with increased waist to hip ratio reported menstrual irregularity which makes 39.55% of the total sample population. Dysmenorrhea was reported by 63.6% of participants and family history was positive in 77.3%. Hirsutism was reported in 36.7% and 49.2%, acne in 34.6% and 43.2%, weight gain tendency in 85.7% and 98.5%, types 2 diabetes in 0% and 4.4% and hypertension in 8.16% and 31.3% of overweight and obese participants respectively. This study shows considerable association between overall and central obesity with menstrual cycle irregularity. This study provides the grounds on which foundation of health promotion and awareness programs can be laid for targeted age group.

Salivary detection of human Papilloma virus 16 & 18 in pre-malignant and malignant lesions of oral cavity: Is it feasible in Pakistani context of Socio-Cultural Taboos?

OBJECTIVE: To evaluate salivary detection of HPV-16 & 18 would be feasible and informative biomarker for oral pre-malignant and malignant lesion in our population. METHODS: This non-interventional, case control study was carried out at department of E.N.T, Head and Neck Surgery, Dow University of Health Sciences, Dow Medical College and Civil Hospital Karachi, Pakistan between July 2011 to December 2012. Total of 105 cases were recruited. These were divided in three groups 'A', 'B' & 'C' having 35 subjects each. Group'A' constitutes patients having strong clinical evidence of oral pre-malignant lesions (PML). Group 'B' includes histologically proven oral squamous cell carcinoma (OSCC) and Group 'C' comprised disease free subjects as controls. After taking informed consent, relevant clinical history was recorded on institutional approved performa. Saliva from all subjects was procured by standard 'drooling method'. Samples were stored at +4°C and later transferred to Laboratory to store at-20°C before further process. Samples were centrifuged at 4500 rpm for 15 minutes at 4°C. Cell pellets sediments were used for identification of HPV-16 & 18 by real-time PCR method. Data was entered and analysed using SPSS version 16. P-value of 0.05 was taken as standard. RESULTS: In group 'A', HPV-16 was detected in 3 (8.6%) cases while HPV-18 was not detected in any of the subject. In group 'B', HPV-16 was detected in 07 (20%) while HPV-18 was found in 06 (17.1%) cases. Mixed HPV-16 and HPV-18 were found in 02 (5.7%) cases. In group 'C', HPV-16 was detected in 03(8.6%) while HPV-18 was not detected in any of the subjects. Significant relationship was observed between the groups for HPV-18 detection (P= 0.002) while for HPV-16, no significant association was found (P= 0.245). CONCLUSION: HPV infection for the causation of oral cancer cannot be fully established possibly due to small sample size. More over differences in genetic makeup, environment, indulgence in peculiar risk factor habits, sexual practices and difficult evaluation of the acquisition of viral load due to socio-cultural and religious restrictions could be the reason.