HRCT Spectrum in Initially COVID-19 RT-PCR Negative Patients

Objective: To analyze radiological spectrum of HRCT in COVID-19 patients, clinically symptomatic but initially having negative RT-PCR. Study Design: Prospective cross sectional descriptive study. Place and Duration of Study: Radiology and Medicine Department, DHQ Hospital Rawalpindi, from June to November 2020 Methodology: The study included 90 patients presenting with clinical symptoms of COVID-19 but with negative RT-PCR. All patients underwent chest computed tomography (CT). Patients with positive COVID-19 RT-PCR test or serology on subsequent repeat test were included in the study. Patients having non COVID-19 HRCT features with negative RT-PCR were excluded from the study. Results: Out of 90 symptomatic, RT-PCR negative patients, 7 had normal chest CT. According to BSTI classification, 50 patients showed classic, 11 had probable and 22 had indeterminate features. Despite supportive clinical and CT features, 17 (18.89%) patients had negative RT-PCR tests on subsequent testing. Unilateral changes were in 8 (8.9%) and bilateral in 75 (83.3%). Most common finding was mixed pattern of peripherally distributed GGN and bronchocentric nodules in 37 (41.1%) patients. Consolidations were in 19 (21.1%), pure ground glass haze in 13 (14.4%), crazy paving in 4 (4.4%), fuzzy bands and arcades in 7 (7.8%), and subtle gravitational GGH in 3 (3.3%) patients. CT-SS classified 69 (76.7%) patients as mild, 10 (11.1%) as moderate and 4 (4.4%) as severe disease. Conclusions: HRCT with CTSS is an important tool for diagnosing and prognosticating COVID-19 infection despite negative RT-PCR, timely identifying and isolating COVID-19 cohorts preventing cross infection and also aiding in prompt symptomatic management

Design of a Low Micro Vibration High Precision CubeSat Reaction Wheel

Rolling element bearings are known to generate higher order harmonics. These harmonics can reach up to the 10th or higher engine order [1]. When wheels are used in a wide speed range, these higher order harmonics can pass and excite rotor eigenfrequencies and rotor modes, severely increasing the exported μ-vibrations at these frequencies. The amplification of these frequencies will then be governed by the quality factor (Q-factor) of the rotor. Single piece rotors have several advantages such as affordable tight tolerances, uniform mass and elimination of assembly errors, but such monolithic metallic structure feature high Q-factors. Material choice is a first way to address this [2], but damping will stay limited. To further increase the internal damping and reduce the Q-factor, Constrained layer damping is employed

Patient going for PRK treatment for refractive error in Al-Jouf region, Saudi Arabia

Introduction: Photorefractive keratectomy (PRK) has been widely used as an efficient, secure, and cost-effective method for treating patients with low to moderate myopia. This study was aimed to evaluate the prevalence of accepted and rejected reasons candidates going for PRK treatment for refractive error in Aljouf region, Saudi Arabia. Material and Methods: This retrospective study was conducted among 255 candidates going for PRK treatment for refractive in the department of ophthalmology at tertiary care hospital in Aljouf region, Saudi Arabia from August 2023 to October 2023.The following measurements of eye were noted for the enrolled patients in the study: visual acuity (VA) sine correction (SC) Visual acuity cum correction (CC), refractive error (RE) Central corneal thickness (CCT), Pentacam Astigmatism, keratometry (K1 and K2), spherical, cylindrical, and axis power in diopters, cycloplegic refraction, and pupillary diameter in normal daytime illumination in a room. Results: Total 255 patients were included in this study among them 119 (46.67%) male and 136 (53.33%) female with average age of 26 in both male and female. Total 160 were fit and 95 were not fit. Visual acuity cum correction (CC) ocular dexter (OD) and Visual acuity cum correction (CC) ocular sinister (OS) reported both statistically significant with p value <0.001. Both K Max OS and K Max OD are statistically significant. The dry eye was evaluated by using Schimer test with mean of 15.00 and 10.00 with p value <0.001 were found significant. Conclusion:  This study concluded that 62.74% were reported fit and 37.26% were not fit for PRK treatment for refractive error because of the dry eye, Keratoconus, rocotane, amblyopia, hyperopia, diabetics and pregnancy in Aljouf region, Saudi Arabia. The Pentacam Astigmatism and dry eye was found statistically significant in both fit and unfit group

Giardiasis in patients with dyspeptic symptoms

AIM: To investigate the prevalence of giardiasis in patients with dyspeptic symptoms. METHODS: Clinical records of consecutive patients who attended Gastroenterology Department at Aga Khan University Hospital from January 2000 to June 2003 and had esophagogastroduodenoscopy (EGD) with duodenal biopsies and international classification of diseases 9th revision with clinical modifications (ICD-9-CM) coded with giardiasis were studied. RESULTS: Two hundred and twenty patients fulfilled the above criteria. There were 44% (96/220) patients who were giardiasis positive, 72% (69/96) of them were males and 28% (27/96) of them were females. There were 65% (81/124) males and 35% (43/124) females who were giardiasis negative. The mean age of patients with giardiasis was 28+/-17 years, while that of giardiasis negative patients was 40+/-18 years (P\u3c0.001). In patients with giardiasis, abdominal pain was present in 71% (68/96) of patients (P = 0.02) and diarrhea in 29% (28/96) (P = 0.005); duodenitis in 25% (24/96) on EGD (P = 0.006) and in 68% (65/96) on histopathology (P = 0.002). CONCLUSION: Giardiasis occurs significantly in young people with abdominal pain, while endoscopic duodenitis is seen in only 25% of giardiasis positive cases, which supports routine duodenal biopsy

Nutritional status in patients with Hepatitis C

OBJECTIVE: To assess the nutritional status via the SGA (subjective global assessment) screening tool of patients at all stages of hepatitis C virus (HCV) liver disease. STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Out-patient Clinics of the Aga Khan University Hospital, Karachi, conducted from October 2009 to January 2011. METHODOLOGY: Patients with hepatitis C virus infection and their HCV-negative attendants were enrolled from the outpatient clinics, and categorized into 4 groups of 100 patients each: healthy controls (HC), those with chronic hepatitis C infection (CHC), compensated cirrhotics (CC) and decompensated cirrhotics (DC). The validated subjective global assessment (SGA) tool was used to assess nutritional status. RESULTS: A total of 400 patients were enrolled. Most of the patients in the HC group were class \u27A\u27 (best nutritional status). In contrast, the majority (64%) in the DC group were in the class \u27C\u27 (worst status). The compensated cirrhosis (CC) group showed that 90% of patients were malnourished, while 98% of all patients were malnourished in the DC group, predominantly class \u27C\u27. Most importantly, 14% of patients with chronic hepatitis C (CHC) also scored a \u27B\u27 on the SGA; which when compared to HC was statistically significant (p=0.005). As the groups progressed in their disease from CHC to DC, the transition in nutritional status from \u27A\u27 to \u27C\u27 between groups was statistically significant. CONCLUSION: Malnutrition occurs early in the course of HCV, and progresses relentlessly throughout the spectrum of HCVdisease

Alu-repeat polymorphism in the tissue plasminogen activator (t-PA) gene, seminal t-PA concentration, and male fertility impairment: A case-control study

Background: Tissue plasminogen activator (t-PA) is a protein involved in the fibrinolytic system that catalyzes the conversion of plasminogen into the active plasmin. The activity of t-PA is controlled by plasminogen activator inhibitor-1. t-PA has crucial functions during spermatogenesis. One polymorphism was reported for t-PA gene, either the presence of a 300-bp Alu-repeat (Alu+) or its absence (Alu−). Objective: The current work aimed at studying the association between Alu polymorphism in the t-PA gene and male infertility. Materials and Methods: Using polymerase chain reaction on genomic DNA isolated from the blood of 79 participants, a region polymorphic for Alu element insertion in t-PA gene was amplified. In addition, total t-PA concentration, plasminogen activator inhibitor-1/t-PA complex concentration, and t-PA activity in seminal plasma were measured by enzyme-linked immunosorbent assay. Results: The results indicate that the percentage of infertile participants (n = 50) who were homozygous for t-PA Alu insertion (Alu+/+), heterozygous Alu+/− or homozygous for t-PA Alu deletion (Alu−/−) did not change significantly (p = 0.43, 0.81, and 0.85, respectively) when compared with the control participants (n = 29). On the other hand, a significant decrease (p = 0.0001) of t-PA total concentration in seminal plasma was observed in the infertile group in comparison with the control group. However, the results indicate that there is no association between the t-PA Alu different genotypes and the total t-PA seminal concentration in the infertile group when compared to the control group (p = 0.63). Conclusion: Data obtained from the current study does not support an association between t-PA Alu polymorphism and t-PA seminal concentration or male infertility. Key words: Alu element, Male infertility, Semen, Spermatogenesis, t-PA

Potential of low carbon nanotubes dosage on chromium removal from water

This paper involves a method of eliminating hexavalent chromium (Cr (VI)) from the synthetic water via a low dosage of carbon nanotubes (CNT). The ability of CNT to remove Cr(VI) from synthetic water through the adsorption process was studied in batch experimentation. The findings revealed up to 100% elimination of Cr(VI) in the 0.07 mg/L Cr(VI) concentration. These excessive elimination proficiencies were credited to the powerful adsorption of chromium ions to the physical properties of the CNT. A pattern layout was created in these experimental runs in order to locate the ideal situation of the Cr(VI) deletion from synthetic water. To accomplish the purposes of the experiment, there were 4 independent variables influencing several points, namely the CNT dosage, the pH of the water, the agitation speed, and the contact time. The StatGraphics Centurion XV software has been used to create the adsorption equivalence and to discover the major impacts to the elimination of Cr(VI). The results show that the adsorption capability of the carbon nanotubes was considerably reliant on the pH of the Cr(VI) solution, supported by the CNT dosage, the contact time, and the agitation speed. The expected optimization, using the adsorption equation, shows that a 1 mg CNT dosage with a pH=2, 120 minutes contact time, and moderate agitation rate at 150 rpm is the most optimal

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries