POLYMORPHIC DELETIONS OF GLUTATHIONE S-TRANSFERASES M1, T1 AND BLADDER CANCER RISK IN ALGERIAN POPULATION

Objective: Glutathione S-transferase mu 1 (GSTM1) and GST theta 1 (GSTT1) genes are two xenobiotic metabolizing genes in Phase II of the detoxification process. The polymorphisms of GSTM1, GSTT1 genes, and smoking are involved in many cancers such as bladder cancer. Our aim was to assess the role of smoking status and GSTM1 and GSTT1 null genotypes in bladder cancer development in Algerian population.Methods: The current case–control study included 175 bladder cancer patients and 188 controls matched for age, gender, and ethnic origin. The GSTM1 and GSTT1 genotypes were determined by multiplex polymerase chain reaction using blood genomic DNA. Possible associations of stage and grade with the obtained genotypes were also tested.Results: A significant associations were observed between bladder cancer risk and tobacco smoke (p value: p=1.21E-08), GSTM1 null genotype (p=0.018), GSTT1 null genotype (p=0.009), and GSTM1/GSTT1-double null genotype (p=0.001). The combined effect of smoking and testing deletions increased the risk of bladder cancer and the most important risk was observed among smokers carrying GSTM1/GSTT1-double null genotype (p=1.09E-05). No significant association was shown between stage and grade of bladder cancer and the testing genotypes.Conclusion: This study indicated that smoking, GSTM1 null, GSTT1 null, and GSTM1/GSTT1-double null genotypes individually represent a risk factor for bladder cancer in Algerian population. The interaction smoking gene increased the risk considerably. In fact, it is suggested that patients with cigarette smoking habit and combined GSTM1 and T1 genes deletion might be at increased risk of bladder cancer

Gain Flatness and Noise Figure Optimization of C-Band EDFA in 16-channels WDM System using FBG and GFF

In this paper, Gain Flatness and Noise Figure of Erbium Doped Fiber Amplifier (EDFA) have been investigated in 16-channels Wavelength Division Multiplexing (WDM). Fiber Bragg Grating (FBG) is used in C-band with the aim to achieve flat EDFA output gain. The proposed model has been studied in detail to evaluate and to enhance the performance of the transmission system in terms of gain, noise figure and eye diagram of the received signals. To that end, various design parameters have been investigated and optimized, such as frequency spacing, EDF length and temperature. To enhance the transmission system performance in terms of gain flatness, the Gain Flattening Filter (GFF) has been introduced in the design. To prove the efficiency of the new design, the optical transmission system with optimized design parameters has been compared with a previous works in the literature. The simulation results show satisfactory performance with quasi-equalized gain for each channel of the WDM transmission system

Chromatic Dispersion Compensation Effect Performance Enhancements Using FBG and EDFA-Wavelength Division Multiplexing Optical Transmission System

An optical transmission system using Fiber Bragg Grating (FBG) and Erbium Doped Fiber Amplifier (EDFA) with new proposed model has been analyzed to overcome chromatic dispersion and attenuation phenomena. To evaluate the transmission system performance of the received signals, a simple model of one channel transmission has been developed in the first step. Also, optical fiber length and attenuation coefficient parameters have been investigated in detail to deal with the optimized corresponding parameter values. Results show that the performance of the optimized design parameters is very efficient in terms of output power (dBm), noise figure (dB), gain (dB), and Q-Factor. The model of one channel developed previously has been adapted to a complex model of four optical channels multiplexing with different wavelengths. FBG and EDFA have been also added to WDM technology system to enhance the chromatic dispersion and the signal attenuation. Results show that the new model is more efficient in terms of Q-Factor and eye diagrams

Melanosis coli

La mélanose colique est une affection bénigne qui découle de l'abus de laxatifs anthraquinoniques. Elle est décrite comme une pigmentation foncée de la muqueuse colique. Elle est souvent liée à la constipation. La mélanose colique est principalement diagnostiquée par l’endoscopie et confirmée par l’histologie. Il est important de reconnaître la mélanose colique qui peut régresser généralement en quelques mois avec l’arrêt des laxatifs. Bien qu'elle soit considérée comme une maladie bénigne, les biopsies endoscopiques doivent être faites sur les zones pigmentées et les zones non pigmentées en raison de la suspicion d'adénome ou de carcinome colorectal associé. A ce propos, nous rapportons tous les cas de mélanose colique colligés au service EFD-Hépato-gastroentérologie à l’hôpital Ibn Sina de Rabat au Maroc. L'évolution était favorable après l'arrêt de l'utilisation de laxatifs chez tous les patients.Melanosis coli is a benign condition that arises from anthraquinone laxative abuse. It is described as a dark pigmentation of colonic mucosa. It is often related with constipation. Melanosis coli is mainly diagnosed by endoscopic and confirmed by histopathology. It is important to recognize the melanosis coli which can be regressed generally in a few months with the discontinuation of laxatives. Although it is seen as a benign disease, colonoscopy biopsies should be taken on the pigmented and not pigmented areas because of the suspicion of associated colorectal adenoma and carcinoma. In this regard we report all cases of melanosis coli enrolled in EFD-hepatogastroenterology unit at ibn sina hospital in Rabat-Morocco. The evolution was favorable after discontinuation of the use of laxative in all patients

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Gene Editing Technology in the Treatment of Cancers and other Genetic Disorders

The field of molecular biology has been transformed by the development of CRISPR/Cas9 gene editing technology, which has opened up previously unimaginable possibilities for the treatment of a variety of genetic diseases, including cancer. The development and potential uses of CRISPR/Cas9 gene editing technology to treat cancer and other genetic disorders are summarized in this abstract.With the help of a The CRISPR/Cas9 system, which includes the Cas9 enzyme and guide RNA, precisely targets and modifies specific DNA sequences by directing Cas9 to a particular DNA sequence with the aid of a guide RNA molecule. This gene-editing tool is based on a natural bacterial defense mechanism and can perform modifications like gene knockout, gene insertion, or gene correction. The system allows for the selection of a specific DNA sequence based on location, function, or association with a particular gene or genetic trait. In particular, CRISPR/Cas9 technology holds great promise for understanding the underlying genetic mechanisms of tumorigenesis and devising innovative therapeutic strategies for cancer treatment. The detection and confirmation of oncogenes and tumor suppressor genes is one use of CRISPR/Cas9 in cancer research. Researchers can clarify the functional roles of particular genes in the initiation and growth of tumors by methodically focusing on these genes in cancer cells. Our understanding of cancer biology is improved by this information, which also offers potential targets for therapeutic intervention. Additionally, CRISPR/Cas9 gene editing has demonstrated significant promise for the creation of individualized cancer treatments. This technology can disrupt or correct cancer-related mutations through targeted gene knockout or correction, potentially restoring regular cellular functions. In the realm of genetic diseases, CRISPR/Cas9 gene editing offers a revolutionary approach to correct disease-causing mutations. Researchers hope to create effective treatments by precisely identifying and altering the genetic flaws that cause various inherited disorders. However, before CRISPR/Cas9 gene editing is widely used in medicine, there are still a number of obstacles to overcome. The main areas that need more research and improvement include off-target effects, delivery methods, and ethical considerations. However, the rapid development and ongoing improvements in CRISPR/Cas9 technology hold great promise for the creation of precise and targeted treatments for cancer and genetic disorders

Fabrication of pyramid/nanowire binary structure on n-type silicon using chemical etching

A pyramid and nanowire binary structure of n-type monocrystalline silicon surface was fabricated by two-step chemical etching process. The nanowire surface is formed by electroless etching in HF-AgNO₃ aqueous solution after being textured in KOH/IPA solution. Optical absorption was compared between this structure and that of random pyramid arrays. The effective reflectance calculated between 400 and 1100 nm decreased from ≈ 40% to ≈ 15% after pyramidal texturing and ≈ 4% after formation of vertically aligned nanowires with a length less than 1 μ m. This simple and low-cost surface structuring technique holds high potential for the manufacture of terrestrial silicon solar cells with reduced optical losses

Improvement of Screen-Printed Textured Monocrystalline Silicon Solar Cell Performance by Metal-Assisted Chemical Etching

AbstractIn this work, we investigate the potential use of stain etched porous silicon as one possible way to increase the silicon solar cell efficiency at low cost. A very simple method for the formation of porous silicon antireflection coatings on random pyramid textured screen-printed monocrystalline silicon solar cells is described. The process is based on electroless metal-assisted chemical etching by immersion of the fully processed cell in HF-H2O2-Ethanol without masking the contacts. Characterization of the porous silicon layer using SEM, EDX and UV-VIS-NIR spectrophotometry revealed that silver nanoparticles that are dissolved from the unmasked front grid contact by the HF acid greatly enhance the dissolution rate and therefore serve as catalysts for the porous silicon etching. The solar cell weighted reflectance was reduced from 45.08% to 22.01% after texturization and dropped further to 11.34% after porous silicon formation under optimized conditions. The porous silicon antireflection layer led to a relative improvement of 24.64% in the short-circuit current density without fill factor deterioration. The open-circuit voltage increased by ∼7mV and the cell efficiency was raised by 2.3% absolute. The simplicity of the process makes it attractive for the cost-effective production of silicon solar cells