25 research outputs found
Aging behavior of intercritically quenched ductile iron
Although extensive aging and strain aging (bake hardening, BH) studies have been carried out on dual-phase steels, the aging behavior of the dual matrix structure (DMS) ductile iron (DI), as a
potential way to improve its mechanical properties, has not been addressed until now. This research
was designed to study the aging behavior of DI with a ferrite-martensite matrix structure. DMS-DI with a martensite volume fraction of 30% was produced by intercritical austenitizing at 785 ◦C followed by quenching in water to room temperature. Aging treatments were carried out without prestraining at aging temperatures of 140, 170, and 220 ◦C for 2–10,000 min. DMS-DI was investigated by light optical microscopy (LOM) for unaged samples and scanning electron microscopy (SEM) for selected samples after aging treatments. The effect of aging conditions on the mechanical properties were investigated. Microhardness measurements for ferrite and martensite were also examined as a function of aging conditions. The increase in yield strength due to aging was determined. The results indicate that the aging conditions have a small effect on the ultimate tensile strength UTS. It is shown that the yield strength increased to a maximum value of 45 MPa (~11% increase) after aging for particular time, which is found to be dependent on the aging temperature. The peak aging response is followed by a decrease in yield strength, which is observed to be attributed to martensite tempering as confirmed by microhardness measurements
Evaluation of Fine-needle Aspiration Cytology (FNAC) Sensitivity Compared to PCR for Diagnosing Tuberculosis Lymphadenitis
Background: Tuberculosis (TB) is a major healthcare burden in Sudan and other developing countries, it is considered the second most common cause of death from infectious diseases after those due to AIDS. In Sudan, TB lymphadenitis (TBLA) remains one of the major health problems. This descriptive cross-sectional study was conducted at the University of Medical Sciences and Technology (UMST) and Total Labcare Diagnostic Center (TDC). The study aims to compare the sensitivity of Fine Needle Aspiration Cytology (FNAC) smears with that of the Polymerase Chain Reaction (PCR) for the diagnosis of TBLA.
Materials and Methods: Fifty-five dry smears were obtained using fine-needle aspiration (FNA) from an enlarged lymph node. PCR was applied to detect the target gene (IS6110). May-Grunwald-Giemsa (MGG) or Diff quick stains were used.
Results: Two (4%) patients with TBLA were non-necrotic, while fifty-three of them (96%) were necrotic. Moreover, 17 (30%) fine-needle lymph node aspiration specimens were confirmed by PCR to be positive for Mycobacterium tuberculosis complex (MTB complex) while 38 (70%) of them were negative.
Conclusion: There was no significant difference between the sensitivity of PCR and that of FNAC (P-value = 0.33)
Is Prolonged Sitting a Risk Factor in Developing Hemorrhoids and Anal Fissures?
Background: Anal fissures and hemorrhoids are common anal conditions. They cause significant morbidity, social embarrassment, and work absenteeism. In addition, they form a significant workload on the healthcare system. Nevertheless, the etiology of these conditions is still contentious. It has been observed that hemorrhoids and anal fissures are associated with prolonged sitting. This study aims to investigate this observation.Methods: This is a case–control study. We compared 81 patients with symptomatic and endoscopically proven hemorrhoids and/or anal fissures with 162 controls with no symptoms or endoscopic evidence of perianal disease. The study was conducted at Khartoum North Teaching Hospital (KNTH) endoscopy unit between January and December 2019. Demographic data, sitting hours per day, and endoscopic findings of patients and controls were recorded in a proforma. The cases and controls were matched for age, sex, and bowel habits. Data were analyzed and compared using the SPSS version 23.Results: The mean sitting hours for cases was 5.99 (SD 3.4) whereas that for controls was 4.0 (SD 3.0) with a highly significant difference (P < 0.001). Sitting for 5 hr or more per day (exposure) was associated with an increased risk of developing hemorrhoids and/or anal fissures [odds ratio 3.68, 95% CI: 2.1–6.47].Conclusion: The study showed that sitting down for 5 hr or more per day might increase the risk of developing hemorrhoids and/or anal fissures. This finding could help in the prevention and treatment of these diseases and the reduction of recurrences
Safety and efficacy of percutaneous nephrolithotripsy in comorbid patients: A 3 years prospective observational study
Purpose: To report the result of percutaneous nephrolithotripsy (PCNL) via standard nephrostomy tract in a single training institution. The perioperative complications in relation to the comorbid state are particularly assessed. Patients and methods: A prospective interventional study between January 2019 to November 2022, included 210 patients scheduled for PCNL. The average age was 40.3 ± 11.8 years (range 18- 67 years). Patients were categorized into two groups. The first group comprised 146 cases (69 .5%) with no associated co-morbidities while the second group 64 (30.5%) had co-morbidities such as obesity in 4 cases (1.9%), hypertension (HTN) in 24 cases (11.4%) cases, diabetes mellitus (DM) in 17 (8.1%) cases, history of recurrent stone surgery in 11 (5.2%) cases and more than one in 8 cases (3.8%). Co-morbidities, stone burden, location of stone, time of surgery, stay in the hospital, further operations, and negative events were among the reported data. Complications and the stone-free rate were the main outcome indicators. Results: Intraoperative complications were reported in 40 (18.8%) patients (18 group 1 and 22 group 2) during PCNL. Bleeding occurred in 22 (10.5%) patients (9 group 1 and 13 group 2), blood transfusions were needed in 4 (1.9%) (2 group 1 and 2 group 2), extravasation was observed in 11 patients (5.2%) (6 group 1 and 5 group 2) and cardiac arrhythmia in 3 (1.4%) (1 group 1 and 2 group 2) patients. Postoperative complications occurred in 61 patients (29%) (24 group 1 and 37 group 2) in the form of fever in 10 patients (4.8 %) (3 group 1 and 7 group 2) and prolonged leakage in 50 patients (23.8%) (21 group 1 and 29 group 2). One patient of group 2 died from postoperative sepsis. Extravasation and postoperative leakage were higher in diabetic patients than in non-diabetics. Stonefree rate was 60.5% (127 of 210). Clinically significant residual fragments (CSRFs) found in 70 cases (33.3%) (33 group 1 and 37 group 2). In 13 cases (6.2%) (5 group 1 and 8 group 2), clinically insignificant residual fragments (CIRFs) were found. In 8 (3 group 1 and 5 group 2) of the 13 cases, spontaneous stone passage was observed within 4-6 weeks of surgery. Residual stones in three cases (1 group 1 and 2 group 2) were asymptomatic and 4 mm or less, whereas stones increased in two cases of group 2. Among all factors studied, stone burden was significantly correlated to both intraoperative and postoperative complications. The occurrence of postoperative fever increased with large stone burden. Conclusions: PCNL is a therapeutic modality that is effective, feasible, and safe for a wide range of patients with concurrent medical issues. A steep curve is required to reduce intraoperative and postoperative complications
Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey
Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Influence of Schroth Best Practice Therapy on Ventilatory Function in Adolescent Idiopathic Scoliosis: Randomized Controlled Study Design
Introduction: Approximately 2%-3% of the population develops idiopathic scoliosis, making it the most prevalent structural spinal deformity in children as well as adolescents. Objective: To find out the efficacy of Schroth Best Practice therapy on pulmonary functions in adolescent idiopathic scoliosis. Methods: Sixty female subjects with adolescent idiopathic scoliosis were recruited from Outpatient Department at AlKasr Al-Ainy Hospital from May 2022 to July 2023 were enrolled in that study. They were randomized into two equivalent groups: Either the intervention group: Group A (Study group) consists of 30 subjects received the Schroth Best Practice exercises program for 18 weeks, or the control group Group B: consists of 30 subjects received traditional exercise program for 18 weeks. Both groups were given 3 sessions a week. Both groups received assessment of pulmonary functions: Forced Vital Capacity (FVC), forced expiratory volume in the first second (FEV1) As well as Peak Expiratory Flow (PEF) on 1st and 18th week. Measuring pulmonary function with digital handheld spirometer before and after treatment. These selective subjects were randomized into two equal groups. Results: There was a statistically significant difference (p<0.05) among the two groups when comparing the mean values of all measured variables pre and post treatment. All analyses were performed at the 0.05 level of significance. With the initial alpha level set at 0.05, in favor of group A. Conclusion: Both Schroth Best Practice exercise program and traditinal exercise program have a significant effect in adolescent idiopathic scoliosis, and the integrated Schroth Best Practice exercise program was more effective than traditional exercise alone
Evaluation of clear aligners attachment success rate with different composite types
This study aimed to evaluate the survival rate of clear aligner attachment using different composite types. Twelve patients ranging from 15 to 25 years old participated in this research. Patients who met the inclusion criteria were randomly assigned to one of two groups: packable composite, which contained packable composite attachments, or flowable composite, which included flowable composite attachments. There was no statistical difference in attachment failures between the two groups for all cases (2 = 3.003, P = 0.083) and individual cases. However, failures occurred in 75% of the FC group vs. 55.6% for the PC group (categorical data were compared using the Chi-Square or Fisher's exact test). According to the findings of this research, the composite type, whether packable or flowable, did not affect attachment failure
Efficiency of different miniscrew positions for maxillary incisor intrusion: A comparative cone beam study
Aim: To evaluate the treatment efficacy of two different position of mini-implant-assisted methods to intrude the maxillary incisors using cone-beam computed tomography (CBCT). Patients and Methods: The study included 26 patients with elongated maxillary incisors and a deep bite, ranging in age from 12 to 18 years. One group received anterior mini-implants, whereas the other received posterior ones at random. The AMG used elastic chains to apply about 40 g of force per side, while the PMG used beta-titanium wires. This investigation used CBCT scans that were performed before and after an intrusion that lasted 18 weeks. Result: Significant changes in the labial inclination of all incisors, which were greater in PMG than AMG. Conclusion: Both mechanics result in increased labial tilting, but posterior mini-implants assisted maxillary incisor intrusion is greater, so it is preferred when the patient's incisors is upright position