Impact of Biofilms on Surface Properties of Polymethyl Methacrylate (PMMA) Resins.

Poly(methyl methacrylate) (PMMA) resins are widely used in medical and dental applications. Their susceptibility to bacterial biofilm formation poses significant challenges related to material degradation and infection risk. This study investigated the effects of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) biofilms on PMMA resin surface properties over a 45-day period at 35°C. The study examined various parameters including biofilm adhesion, morphology, surface roughness, hydrophobicity, solid fraction, and zeta potential. PMMA resin specimens were inoculated with bacteria and incubated for 45 days. Biofilm adhesion was visually assessed, while surface characterization was conducted using scanning electron microscopy (SEM), atomic force microscopy (AFM), roughness analysis, contact angle measurements, solid fraction determination, and zeta potential analysis. The P. aeruginosa and S. aureus isolates were selected based on their biofilm-positive characteristics, which were further confirmed using Congo red and biofilm formation assays through crystal violet staining and spectrophotometric analysis. The results demonstrated robust biofilm adhesion on PMMA surfaces. SEM and AFM imaging revealed textured surfaces with elevated structures and depressions within the biofilm matrix. Biofilm-exposed resins exhibited significantly increased roughness (Ra = 164.5 nm, Rq = 169.5 nm) and hydrophobicity (mean angle = 85.5°-90.5°) compared to control samples (Ra = 38-50 nm, angle = 55°). Solid fraction measurements indicated a denser biofilm matrix on exposed resins (0.908) compared to controls (0.65). Additionally, zeta potential values were more negative for biofilm-exposed resins (mean = -84.2 mV) than controls (-45.0 mV). These findings underscore the substantial alterations in PMMA resin surface properties induced by bacterial biofilms, emphasizing the critical need for strategies to prevent biofilm formation and mitigate associated risks in healthcare settings. Future research should focus on developing anti-biofilm coatings or treatments to preserve the integrity and functionality of PMMA materials.

Student's opinion regarding teaching methods: A survey amongst MBBS and BDS students of a private Medical University in Karachi - Short Communication.

A cross sectional study was conducted in a private medical university among undergraduate MBBS and BDS students, to ascertain their opinion regarding various teaching methods. Convenience sampling technique was utilized with data collection spanning over March to August 2015 on a sample of 398 students. A self-administered questionnaire was used for the purpose. Descriptive analysis was applied for numerical data while chi square was used for categorical data. P value under 0.05 was considered significant. Our results showed that around 120 (30%) of the participants supported PBL as the most effective teaching method while 64(16%) considered clinical rotations, and 60(15%) voted for lectures. According to undergraduate students Problem-based Learning is the most significant tool for learning. Integrated method of teaching was endorsed by both MBBS and BDS students.

Evaluation of techno-economic design andimplementation of solar-wind hybrid microgridsystem for a small community.

Pakistan is faces significant challenges in meeting its energy demand and consumption needs for consumers. This country's energy production from primary sources such as petroleum and natural gasses is incompetent in fuel-use and hence unable to meet feasibility cost. With an increasing population, Pakistan's energy consumption per capita has been steadily rising. This behaviour is leading to critical energy issues, especially in remote rural areas. This trend in rising energy costs and demand factors are similar to those in the energy markets in the South and South-East Asia. The primary energy sources in Asia continent, including fossil fuels, are insufficient supply to meet this growing demand in production and thus resulting in frequent electricity blackouts. Consequently, renewable energy sources such as solar photovoltaic (PV) and wind power have substantially started to produce energy and to provide a huge portion of Pakistan's daily energy needs apart in conventional energy currently. However, these sources are not yet as reliable, conventional energy bases have a challenge for sustainable energy production. As a result, renewable energy factors nonetheless initial started have effectively stabilized energy consumption, particularly for green electricity with net-zero carbon emissions. The aim of this study is to evaluate the feasibility and cost-effectiveness of integrating a microgrid hybrid system with combined (solar PV/wind power) renewable energy as well as conventional fossil fuel generators. This evaluation focuses on predicting energy production and its costs using Hybrid Optimization of Multiple Energy Resources (HOMER) software, and to enhance the electricity standards at NUST (National University for Sciences and Technology), Pakistan. The proposed methodology of microgrid hybrid system, when evaluated using HOMER software, shows a significant improvement in energy stability and cost efficiency. Moreover, this proposed system can reduce reliance on fossil fuels by a substantial percentage, enhances the predictability of energy production, and optimizes its energy consumption. These can achieve better performance metrics in terms of reliability, cost, and environmental impact; feasible solution for Pakistan and the developing countries. This proposed methodology offers a novel approach by integrating renewable energy sources with conventional generators to create a balanced and efficiency factor by microgrid system. This hybrid system goals as an investigation is to optimize this energy production, reduce carbon emissions, and provide a more stable and cost-effective energy supply.

Smart transactive energy based approach for planning and scheduling in multi-looped microgrid distribution network across planning horizon.

In this paper, an innovative transactive energy approach is proposed as viable option for coordinated distribution system planning across a certain horizon. The proposed approach is evaluated across a multi-looped (meshed) test system and is implemented with load growth having prosumers participating in the electrical market in transactive energy system aiming at evaluation on techno-economic basis. Apart from prosumer sensitivity analysis, evaluations have been carried across reducing total production cost of energy, reduction in per unit price, active power losses. Whereas improving voltage profile, cost of scheduling and consumer per kWh purchase and sales in comparison with traditional counterpart. The proposed framework includes optimization algorithm aiming at sources scheduling and IEEE 69 system for validation. The algorithm minimizes cost, maximizes energy efficiency, increases renewable energy mix and reduces consumers cost of energy purchase. Reduction of 51.44 % in cost of energy is achieved, whereas loss reduction of 12.6% is achieved. The comparison of IEEE 69-bus base case with the 10 %, 15% and 20% transactive energy applied with simulations to evaluate performance parameters that will directly benefit both prosumers and utility alike in-terms of low bills and further reduction of stress on the grid amid load growth across multiple years.

Examining the interplay of dust and defects: A comprehensive experimental analysis on the performance of photovoltaic modules.

The performance of photovoltaic (PV) modules is greatly impacted by dust accumulation and defects appearing in photovoltaic (PV) modules. Existing studies primarily focus on the effect of dust on general photovoltaic performance, neglecting the interactions with pre-existing defects such as snail trails. These defects are known to degrade the efficiency of PV modules. However, their interaction with environmental factors like dust accumulation has not been extensively analyzed. This research comprehensively analyzes the impact of dust accumulation on the performance of PV modules affected by snail trails. Using an experimental setup under outdoor conditions, the study incorporates thermal imaging, current-voltage characteristic curve tracing (IV curve tracing), electroluminescence (EL) imaging, and chemical analysis of the accumulated dust, to evaluate the electrical and thermal parameters affecting PV module performance. The study focuses on three types of modules, clean serves as a reference module (PV-R), normal unclean (PV-N), and snail trail-affected unclean PV module (PV-S). Compared to the PV-R module, the study meticulously quantifies the effect of accumulated dust on key performance indicators such as output power, V, and I. The PV-N module exhibits reductions of 17.7 % in current, 3.91 % in voltage, and 18.15 % in power output. The PV-S module experienced a decrease of 7.4 % in current, 7.55 % in voltage, and 14.87 % in power output under the dust deposition density of 6.984 g/m^2 having a mean particle size of 2.2279 µm. The dust deposition reduced the transmittance of glass, which indicates a potentially adverse impact on the PV module's efficiency. The findings highlighted in the current work provide a significant understanding of the detrimental impacts of dust accumulation on defected photo voltaic modules, highlighting the need for regular maintenance and cleaning to ensure optimal performance.

Novel mutation in AAA domain of BCS1L causing Bjornstad syndrome.

Bjørnstad syndrome is an extremely rare condition characterized by pilitorti and nerve deafness. Only few large families have been reported worldwide. Here we describe a large Pakistani family with five affected individuals. The hair fibers of all the patients were twisted around their axis and devoid of any pigment. In addition the patients had a moderate-to-severe degree of hearing impairment. Genotyping with high-density single-nucleotide polymorphism arrays showed homozygosity in two intervals on chromosome 2. Linkage with one of these regions (genomic position 218745685-221025443, hg19) was confirmed. This region encompasses the BCS1L gene. Mutations in this gene have previously been associated with Bjørnstad's syndrome. We sequenced the BCS1L gene for identification of the causative mutation in the family. A novel homozygous missense mutation c.901T>A was identified, which segregated with the disease in the family. This mutation results in the amino acid change p.Tyr301Asn and was predicted to be pathogenic by bioinformatics tools.

Study of PKRBD in HCV genotype 3a infected patients in response to interferon therapy in Pakistani population.

BACKGROUND: Hepatitis C virus (HCV) is a major cause of liver cirrhosis and hepatocellular carcinoma and infects about 3% world population. Response to interferon therapy depends upon the genotype of the virus and factors associated with the host. Despite a good response to interferon therapy, a considerable number of genotype 3a infected patients remains unalleviated. RESULTS: In total forty-nine patients including twenty-five non-responders (non-SVR) and twenty-four responders (SVR) were recruited. Patients were tested for viral status at different intervals and the isolated RNA was sequenced for the NS5A region in both groups. The comparison of PKRBD of HCV between the SVR and non-SVR patients did not confirm any significant difference in the number of mutations. However, when the sequence downstream to the PKRBD of NS5A was compared, two important statistically significant mutations were observed; at positions 2309 (Ala to Ser) and 2326 (Gly to Ala). These mutations were then analysed for tertiary protein structure and important structural changes were observed. Statistically significant difference was also observed when age groups of patients were compared; younger patients showed better response than the older ones. CONCLUSIONS: The region between PKRBD and IRRDR may be important for prediction of response to IFN therapy for genotype 3a. ISDR and PKRBD have not shown any involvement in treatment response. Further functional analyses of these findings can help in understanding the involvement of the NS5A region in interferon treatment of HCV-3a infected patients.

Tumor necrosis factor-alpha gene promoter region polymorphism and the risk of coronary heart disease.

BACKGROUND: Tumor necrosis factor-alpha (TNF- α ) gene polymorphisms have been implicated in the manifestation of atherosclerosis. Controversy exists regarding the link between the cytokine's variant genotype and CHD among different ethnic groups. There have been fewer studies on the TNF- α gene -1031T>C and -863C>A polymorphisms in relation to CHD. Therefore, the current study was designed to investigate the association of the TNF- α gene -1031T>C and -863C>A polymorphisms with CHD in a Pakistani population. METHODS: Patients with CHD (n = 310) and healthy individuals (n = 310) were enrolled in this study. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: A significant difference was observed in the -863C>A polymorphism between patients with CHD and control subjects (P < 0.0001). CHD risk was positively associated with the variant allele -863A (P < 0.0001) in the study subjects. There was no significant link between the -1031T>C polymorphism and CHD risk in the study population. Haplotypes A-T and A-C of the TNF-alpha gene loci at -863 and -1031 showed higher frequency in the patient group compared with controls (P < 0.05). CONCLUSION: The TNF- α -863C>A gene polymorphism was associated with the pathogenesis of CHD while the -1031T>C polymorphism did not show any link with the disease in a Pakistani population.

Framework for the analysis of renewable energy grid policies in the context of COVID-19.

COVID-19 is a severe global pandemic that has caught the whole world unprepared. In the absence of a clear timeline for this pandemic to end, it is need of the hour to investigate the effect of this pandemic on both previous and anticipated investments. Global economic unrest has hindered the ramping deployment of Renewable energy projects. The most quick actions that may be taken to mitigate the effects and to up-rise the investment portfolio policies are a very critical tool in hands of government for a very immediate effect have also been made without keeping the context of COVID-19 into account. New variants of diff rent nature are being discovered and every now and then new lock downs are happening. In this context different policies have to be evaluated under the pandemic scenario. A case study of a large scale renewable energy project for a higher education institute in Pakistan is being used to measure the difference during COVID and pre COVID times. This paper provides a framework to investigate the impact of COVID on renewable energy system projects under current net-metering, net-billing and self-consumption policies. A recent investment in a photovoltaic system is assessed based on previously projected financial benefits versus the pandemic effected ones. This research concludes that investing in photovoltaic systems are still a viable option even in an extreme pandemic situation with less than 0.5 years increase in payback period, and the government can still provide a stimulus for investing in green energy by implementing net-metering policies on a larger scale.

Racial and Ethnic Differences in Genomic Profiling of Early Onset Colorectal Cancer.

The incidence and mortality of early onset colorectal cancer (EOCRC) is rising; outcomes appear to differ by race and ethnicity. We aimed to assess differences in mutational landscape and gene expression of EOCRC by racial and ethnic groups (non-Hispanic Asian, non-Hispanic Black, non-Hispanic White, White Hispanic) using data from the American Association for Cancer Research Project GENIE (10.2) and University of Texas Southwestern, the latter enriched in Hispanic patients. All statistical tests were 2-sided. Of 1752 EOCRC patients, non-Hispanic Black patients had higher rates of KRAS mutations (60.9%; P = .001, q = 0.015), and non-Hispanic White and non-Hispanic Black patients had higher rates of APC mutations (77.1% and 76.6% among non-Hispanic White and non-Hispanic Black patients, respectively; P = .001, q = 0.015) via the Fisher exact test with Benjamini-Hochberg correction. Using R packages DESeq2 and clusterProfiler, we found that White Hispanic patients had increased expression of genes involved in oxidative phosphorylation (P < .001, q = 0.025). Genomic profiling has the potential to identify novel diagnostics and influence individualized treatment options to address the currently limited prognosis of EOCRC.

Ablative Radiation Therapy in Oligometastatic Pancreatic Cancer to Delay Polyprogression, Limit Chemotherapy, and Improve Outcomes.

PURPOSE: The oligometastatic state is observed in patients across many malignancies, with increased recognition regarding improved outcomes after local therapies. However, there is limited data specifically regarding pancreatic ductal adenocarcinoma. We hypothesized that an oligometastatic pancreatic ductal adenocarcinoma (OPanc) phenotype would benefit from stereotactic ablative radiation therapy (SABR) to all active metastatic sites. Here, we report our institutional experience of SABR-treated OPanc to evaluate the feasibility of the approach. METHODS AND MATERIALS: A retrospective review of patients with synchronous or metachronous OPanc (1 to 5 metastases) who received SABR to all active metastatic sites was performed. We identified a comparable group of patients with similar metastatic burden, range of CA19-9 levels, and no progression for at least 5 months who did not receive SABR. We compared overall survival as the primary outcome, and polyprogression-free survival and time off chemotherapy as the secondary exploratory assessments. A third group presenting with stage IV pancreatic ductal adenocarcinoma and more than 5 distant lesions (polymetastatic) was identified to help define expected outcomes after polyprogression. RESULTS: Our study included 20 patients with OPanc receiving SABR and 21 who did not. SABR was delivered to 38 metastatic tumors. Out of the 20 SABR-treated OPanc patients, 17 (85%) had 6 or more months of time off chemotherapy, compared with 7 patients (33.3%) among the chemotherapy-treated group. Median polyprogression-free survival was 40 and 14 months (hazard ratio = 0.2; 95% confidence interval, 0.07-0.54; P = .0009), and overall survival was 42 and 18 months (hazard ratio = 0.21; 95% confidence interval, 0.08-0.53; P = .0003), for SABR- and chemotherapy-treated cohorts, respectively. CONCLUSIONS: Management of OPanc with SABR as local regional therapy could improve outcomes in a selected population and warrants prospective evaluation.

Primary Ewing sarcoma of the brain: a case report and literature review.

Ewing sarcoma, along with peripheral primitive neuroectodermal tumor, belongs to a tumor family that shares clinicopathologic and molecular genetic features, including the characteristic chromosomal translocation that results in the fusion of the EWS gene on 22q12 to either the FLI1 gene on 11q24 or other Ets family transcription factor gene, such as the ERG gene on 21q22. In contrast, such translocations are not found in central primitive neuroectodermal tumors (cPNETs), such as medulloblastoma and supratentorial PNET. Ewing sarcoma has only rarely been noted to primarily involve the central nervous system-extraosseous Ewing sarcoma (CNS-EES). We report a case of a 7-year-old girl with an anterior cranial fossa mass. Pathology showed a primitive small blue cell tumor with focal Homer Wright rosette formation. The positive membranous immunostaining for CD99 and the EWS-FLI1 fusion demonstrated by fluorescence in situ hybridization studies confirmed the diagnosis of CNS-EES. Although CNS-EES may look identical to cPNETs, these tumors differ in histogenesis, molecular characteristics, and clinical behavior. Demonstration of characteristic translocations by molecular studies differentiates CNS-EES from cPNET and help clinicians make informed decisions regarding therapy.

Frequency of Common CYP2C9 Polymorphisms and Their Impact on Warfarin Dose Requirement in Pakistani Population.

Polymorphisms in cytochrome P450 (CYP) 2C9 (CYP2C9) gene result in interindividual variability in warfarin dose requirement. There is a need for characterization of genotype frequency distribution in different populations for construction of customized dosing algorithms to enhance the efficacy and reduce the toxicity of warfarin therapy. This study was carried out in Pakistani population to evaluate the contribution of common CYP2C9 polymorphisms to warfarin therapy. A total of 550 stable patients taking warfarin were enrolled after medical history, physical examination, and laboratory investigations. Single blood sample was collected after informed consent. Genomic DNA was extracted, and genotype analysis for CYP2C9*2 and CYP2C9*3 polymorphisms was done by polymerase chain reaction-restriction fragment length polymorphism assay. A number of samples were also analyzed by direct DNA sequencing for validation of the results. Data were analyzed using SPSS version 20. Genotype frequency distribution of CYP2C9*2 and CYP2C9*3 was found to be different from other populations. Of these 2 polymorphisms, CYP2C9*2 did not demonstrate significant effect on warfarin dose requirement, whereas CYP2C9*3 did show significant effect ( P value = .012). It is concluded that there is a need to study genotype frequency distribution and their effect on warfarin dose variability among different populations due to diversity in outcome.

A homozygous FITM2 mutation causes a deafness-dystonia syndrome with motor regression and signs of ichthyosis and sensory neuropathy.

A consanguineous family from Pakistan was ascertained to have a novel deafness-dystonia syndrome with motor regression, ichthyosis-like features and signs of sensory neuropathy. By applying a combined strategy of linkage analysis and whole-exome sequencing in the presented family, a homozygous nonsense mutation, c.4G>T (p.Glu2*), in FITM2 was identified. FITM2 and its paralog FITM1 constitute an evolutionary conserved protein family involved in partitioning of triglycerides into cellular lipid droplets. Despite the role of FITM2 in neutral lipid storage and metabolism, no indications for lipodystrophy were observed in the affected individuals. In order to obtain independent evidence for the involvement of FITM2 in the human pathology, downregulation of the single Fitm ortholog, CG10671, in Drosophila melanogaster was pursued using RNA interference. Characteristics of the syndrome, including progressive locomotor impairment, hearing loss and disturbed sensory functions, were recapitulated in Drosophila, which supports the causative nature of the FITM2 mutation. Mutation-based genetic counseling can now be provided to the family and insight is obtained into the potential impact of genetic variation in FITM2.