Multidrug-Resistant Pathogens in Wound Infections: A Systematic Review.

This systematic review aimed to explore the antimicrobial activity of a silver-containing gelling fiber dressing against multidrug-resistant organisms (MDROs) in wound infections. It particularly focuses on burn wounds and evaluates its potential clinical significance in combating antimicrobial resistance. A comprehensive literature search was conducted across multiple databases over the past ten years. It is used to identify relevant studies addressing MDRO infections in wound care and exploring novel antimicrobial approaches. The included studies underwent rigorous methodological assessment. Additionally, the data were synthesized to evaluate the efficacy of silver-containing dressings in inhibiting MDRO growth and eradicating biofilm-associated bacteria. Moreover, this review revealed that silver-containing dressings have constant in vitro antimicrobial activity against 10 MDROs over seven days in simulated wound fluid. However, inhibitory and bactericidal effects were consistently observed against free-living and biofilm phenotypes. The findings suggest potential clinical significance in managing MDRO infections in wounds. This highlights its role in mitigating treatment failure and antimicrobial resistance. Despite the promising implications for wound management practices, this study acknowledges some limitations. In vitro models and the absence of direct clinical validation have also been included. However, the review explains the importance of new approaches. Nanotechnology has been used to address antimicrobial resistance in wound care. Thus, further research and innovation are needed to improve patient outcomes and combat antimicrobial resistance.

Physical properties and pharmacological applications of Co3O4, CuO, NiO and ZnO nanoparticles.

Nano materials have found developing interest in biogenic approaches in the present times. In this study, metal oxide nanoparticles (NPs) such as cobalt oxide (Co3O4), copper oxide (CuO), nickel oxide (NiO) and zinc oxide (ZnO), were synthesized using a convenient and rapid method. The structural features of synthesized metal oxide NPs were studied using various microscopic and spectroscopic techniques like SEM, TEM, XRD, FTIR and EDX. The characterization results confirmed that the prepared NPs possess highly pure, unique and crystalline geometry with size ranging between 10 and 20 nm. The synthesized nanoparticles were successfully employed for pharmacological applications. Enzyme inhibition potential of NPs was evaluated against the urease and tyrosinase enzymes. The percent inhibition for the urease enzyme was observed as 80 to 90% by using Co3O4, CuO, NiO and ZnO NPs while ZnO NPs were found to have best anti-urease and anti-tyrosinase activities. Moreover, effective inhibition was observed in the case of ZnO NPs at IC50 values of 0.0833 and 0.1732 for urease and tyrosinase enzymes which were comparable to reference drugs thiourea and kojic acid. The lower the IC50 value, higher the free radical scavenging power. Antioxidant activity by DPPH free radical scavenging method was found moderately high for the synthesized metal oxide NPs while best results were obtained for Co3O4 and ZnO NPs as compared to the standard ascorbic acid. Antimicrobial potential was also evaluated via the disc diffusion and well diffusion methods. CuO NPs show a better zone of inhibition at 20 and 27 mm by using both methods. This study proves that the novel metal oxide NPs can compete with the standard materials used in the pharmacological studies nowadays.

A molecular simulation study on amine-functionalized silica/polysulfone mixed matrix membrane for mixed gas separation.

Polysulfone (PSF) based mixed matrix membranes (MMMs) are one of the most broadly studied polymeric materials used for CO2/CH4 separation. The performance of existing PSF membranes encounters a bottleneck for widespread expansion in industrial applications due to the trade-off amongst permeability and selectivity. Membrane performance has been postulated to be enhanced via functionalization of filler at different weight percentages. Nonetheless, the preparation of functionalized MMMs without defects and its empirical study that exhibits improved CO2/CH4 separation performance is challenging at an experimental scale that needs prior knowledge of the compatibility between the filler and polymer. Molecular simulation approaches can be used to explore the effect of functionalization on MMM's gas transport properties at an atomic level without the challenges in the experimental study, however, they have received less scrutiny to date. In addition, most of the research has focused on pure gas studies while mixed gas transport properties that reflect real separation in functionalized silica/PSF MMMs are scarcely available. In this work, a molecular simulation computational framework has been developed to investigate the structural, physical properties and gas transport behavior of amine-functionalized silica/PSF-based MMMs. The effect of varying weight percentages (i.e., 15-30 wt.%) of amine-functionalized silica and gas concentrations (i.e., 30% CH4/CO2, 50% CH4/CO2, and 70% CH4/CO2) on physical and gas transport characteristics in amine-functionalized silica/PSF MMMs at 308.15 K and 1 atm has been investigated. Functionalization of silica nanoparticles was found to increase the diffusion and solubility coefficients, leading to an increase in the percentage enhancement of permeability and selectivity for amine-functionalized silica/PSF MMM by 566% and 56%, respectively, compared to silica/PSF-based MMMs at optimal weight percentage of 20 wt.%. The model's permeability differed by 7.1% under mixed gas conditions. The findings of this study could help to improve real CO2/CH4 separation in the future design and concept of functionalized MMMs using molecular simulation and empirical modeling strategies.

Energy, exergy, economic, environment, exergo-environment based assessment of amine-based hybrid solvents for natural gas sweetening.

Natural gas is the cleanest form of fossil fuel that needs to be purified from CO2 and H2S to diminish harmful emissions and provide feasible processing. The conventional chemical and physical solvents used for this purpose have many drawbacks, including corrosion, solvent loss, high energy requirement, and the formation of toxic compounds, which ultimately disrupt the process and affect the environment. Hybrid solvents have lately been researched to cater to these liabilities and enhance process economics. This study screened eight solvents based on CO2 selectivity viscosity, absorption enthalpy, corrosivity, working capacity, specific heat, and vapor pressure. From the screened solvents, ten cases of hybrid solvents are simulated and optimized on Aspen HYSYS®. Furthermore, 5Es (Energy, Exergy, Economic, Environmental, and Exergy-environmental) analyses were performed on optimized cases, and results were compared with the base case, MEA (30 wt%). The hybrid blend of Sulfolane and MDEA with weight percentages of 6% and 24%, respectively, showed the highest energy savings of 20% concerning the base case. In addition, it offered 93% savings in exergy destruction and 17.26% in the total operating cost of the process. It is also promising to the environment due to reduced entropy sent to the ecosystem and controlled CO2 emissions. Therefore, the blend of Sulfolane and MDEA is proposed to Supersede the conventional solvent MEA for the natural gas sweetening process.

Modelling and optimization study to improve the filtration performance of fibrous filter.

Fibrous filter made up of non-woven material was utilized in many industrial applications for increasing the collection efficiency and the quality factor. But there exists a competing effect among the fibre diameter, filtration efficiency, pressure drop, and sometime type of aerosol (liquid or solid) plays a crucial role in the performance of the fibrous filter. To avoid overdesigning of the filter along with better performance, optimum set of parameters are to be decided before the manufacturing process. In the current effort, the desirability approach and along with the "Response Surface Methodology (RSM)" were considered to optimize filtration efficiency and pressure drop simultaneously. In this perspective, the impact of Filtration velocity (v), Basis weight (φ), Particle diameter (dp), and Packing fraction (α) on filtration efficiency (η) and pressure drop (Pd) was studied. Based on the outcome, the predicted values lie within experimental data through smart agreement. The maximum percentage (%) error was only 3% and 6% filtration efficiency (η) and pressure drop (Pd), which determine the effectiveness of this useful model. The most dominant factor which affects the filtration efficiency (η) was found to be the Basis weight (φ), followed by packing fraction. However, in the case of pressure drop, the most dominant factors were filtration speed followed by the pachining fraction. Moreover, artificial neural network (ANN) models are developed for the prediction of filtration efficiency and pressure drop. The model accuracy has been estimated by calculating "Mean Square Error (MSE), Mean Absolute Error (MAE), and coefficient of determination (R2)". Both models show promising results when compared with experimental data with the R2 value of 98.50-99.86. The optimized values of the maximum filtration efficiency and minimum pressure drop simultaneously were obtained for v = 5, φ = 59.60, dp = 52.23, α = 0.24 according to desirability approach.

Exergy, advance exergy, and exergo-environmental based assessment of alkanol amine- and piperazine-based solvents for natural gas purification.

Purification of Natural gas is vital for utilizing it as a source of energy harvesting for the world. Amine-based chemical absorption technique is the most utilized in the gas field for the purification of gas that ensures the purity of the sweet gas stream with the elimination of carbon dioxide. However, it is considered an energy-intensive process to deal with considerable energy loss and environmental damage to the ecosystem. Five cases have been developed in this study based on various blends comprising mono and tertiary amines in combination with piperazine with a focus on the use of Aqueous Monodiethanolamine (Aq. MDEA), Aqueous Monoethanolamine (Aq. MEA) and piperazine (Pz) for the CO2 sequestration from the sour natural gas extracted from the remote location located in the province of Baluchistan in Pakistan. The use of exergy, advanced exergy, and exergo environment for optimizing and selecting a suitable solvent combination that may result in an effective separation process has been proposed. Five cases have been developed based on various blends such as mono and tertiary amines combined with piperazine. From the results of all the studied scenarios, Case IV, based on the combination of Aqueous monoethanolamine and piperazine, provides reduced exergy destruction of 2551.7 KW. It was observed that the maximum removal of CO2 around 99.87 wt% is achieved in case IV. In addition, advance exergy analysis also highlights that case-IV has a venue of 25% exergy destruction avoidable, which would further enhance its performance. Nevertheless, still, case-IV has 75% exergy destruction unavoidable. The environmental factors show that Case-IV has a reduced exergy destruction factor of 0.96, a highly environmentally benign choice as a solvent with a high value of 1.03, and case-IV has the higher operational stability and higher exergy efficiency with an exergy stability value of 0.40. Therefore, monoethanolamine combined with piperazine to be an effective and efficient solvent blend that could be an energy-effective approach for sweetening the natural gas.

Electrochemical monitoring of bisphenol-s through nanostructured tin oxide/Nafion/GCE: A solution to environmental pollution.

Over the past few decades, phenolic compounds have been broadly exploited in the industries to be utilized in several applications including polycarbonate plastic, food containers, epoxy resins, etc. One of the major compounds in phenolics is Bisphenol-S (BPS) which has dominantly replaced Bisphenol-A in several applications. Phenolic compounds are extensively drained into the environment without proper treatment and cause several health hazards. Thus, to tackle this serious problem an electrochemical sensor based on SnO2/GCE has been successfully engineered to monitor the low-level concentration of BPS in water samples. The fabrication of SnO2 nanoparticles (SnO2 NPs) was confirmed through FTIR, XRD, and TEM to examine the size, crystallinity, internal texture, and functionalities of the prepared material. The fabricated material was exploited as a chemically modified sensor for the determination of BPS in water samples collected from different sources. Under optimal conditions such as scan sweep 100 mV/s, PBS electrolyte pH of 6, potential window (0.3-1.3 V), the proposed sensor manifested an excellent response for BPS. The LOD of the present method for BPS was calculated as 0.007 µM, respectively. Moreover, the stability and selectivity profile of SnO2/GCE for BPS in the real matrix was examined to be outstanding.

An improved electrochemical sensor based on triton X-100 functionalized SnO2 nanoparticles for ultrasensitive determination of cadmium.

The drastic increases in the concentration of heavy metals ions in the environment have become a serious concern for a number of years. Heavy metals pose serious impacts on human and aquatic life and cause severe health hazards. Amongst heavy metals, cadmium is known for its lethal effects on human health as it easily reacts with enzymes and creates free radicals in the biological system that causes carcinogenicity and other serious diseases. Thus, to tackle this challenge, TX-100 SnO2 nanoparticles based chemically modified sensor is introduced to assess the quantity of Cd+2 in the water system. The engineered SnO2 nanoparticles were electrochemically characterized through cyclic voltammetry and electrochemical impedance spectroscopy to ensure the better charge transfer kinetics and electrocatalytic properties of fabricated sensors. Under the optimized conditions e.g., scan rate 80 mV/s, PBS electrolyte pH 7, and potential window (-0.2 to -1.4 V), the engineered TX-100/SnO2/GCE-based sensor manifested a phenomenal response for cadmium ions in water media. The LOD and LOQ of developed TX-100/SnO2/GCE were calculated in the nanomolar range as 0.0084 nM and 0.27 nM. The recovery values of the proposed method for Cd+2 were found in an acceptable limit that witnesses the effectiveness of the fabricated sensor. Moreover, the excellent stability and anti-interference behavior of the sensor highlights its dynamic profile to be commercially utilized for the determination of Cd+2 ions in water bodies.

Multiscale Principal Component Analysis-Signed Directed Graph Based Process Monitoring and Fault Diagnosis.

The chemical process industry has become the backbone of the global economy. The complexities of chemical process systems have been increased in the last two decades due to online sensor technology, plant-wide automation, and computerized measurement devices. Principal component analysis (PCA) and signed directed graph (SDG) are some of the quantitative and qualitative monitoring techniques that have been widely applied for chemical fault detection and diagnosis (FDD). The conventional PCA-SDG algorithm is a single-scale FDD representation origin, which cannot effectively solve multiple FDD representation origins. The multiscale PCA-SDG wavelet-based monitoring technique has potential because it easily distinguishes between deterministic and stochastic characteristics. This study uses multiscale PCA-SDG to detect, diagnose the root cause and identify the fault propagation path. The proposed method is applied to a continuous stirred tank reactor system to validate its effectiveness. The propagation route of most process failures is detected, identified, and diagnosed, which is well-aligned with the fault description, demonstrating a satisfactory performance of the suggested technique for monitoring the process failures.

Clinical Presentation, Diagnostic Approach, Laparoscopic Evaluation and Treatment of Impalpable Testis.

OBJECTIVE: To find out the clinical presentation, utility of ultrasound for diagnosis, laparoscopic findings and treatment for clinically impalpable testis. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Department of Paediatric Surgery, National Institute of Child Health, Jinnah Sindh Medical University Karachi, from September 2019 to April 2020. METHODOLOGY: Patients with clinically impalpable testis were included. Ultrasound of inguinal region was done to locate testis. Presence of testis and its position was confirmed at laparoscopy and surgical procedure done according to the findings. Data was stratified according to the age and Chi-square test and Student t-test were applied to find out statistical significance among different variables in children below and above five years of age. A p <0.05 was taken as significant. RESULTS: Ninety-one patients with 113 testes were included. The median age of the children was 48 months. Sixty-nine (75.8%) patients had unilateral undescended testis and 22 (24.2%) bilateral undescended testes. Fifty-three (58.2%) patients were less than five years of age. On ultrasound, testis was found near deep ring in 23 (25.3%) patients. At laparoscopy, 74 (81.3%) testes were found within the abdominal cavity. In 7 (7.7%) patients, only nubbin of tissue was identified and removed. The first stage of Fowler Stephen procedure was done in the majority of the patients. There was statistically no significant difference following stratification in relation to laterality and position of undescended testis (p = 0.556 and p = 0.846, respectively). However, mean size of the testis was found statistically significant (p = 0.032). CONCLUSIONS: Most of the patients were above five years of age. Ultrasound helped in identifying low-lying intra-abdominal testis in more than 80% of patients. Laparoscopy was helpful in further defining the position of the testis and selection of surgical procedure. KEY WORDS: Undescended testis, Cryptorchidism, Laparoscopy, Orchiopexy.

Plant extract-based green fabrication of nickel ferrite (NiFe2O4) nanoparticles: An operative platform for non-enzymatic determination of pentachlorophenol.

Environmental pollution has become a major human concern with the extensive exploitation of pesticides. Pentachlorophenol (PCP) is the most hazardous of all chlorophenols which are being used as pesticide, fungicide, and wood preservative. Thus, the fabrication of ultrasensitive electrochemical methods for the determination of pesticides is of great significance. In the present experiment, a simple, green, and sensitive electrochemical sensor was constructed for the determination of PCP by using a chemically modified nickel ferrite glassy carbon electrode (NiFe2O4/GCE). The fabricated nanoparticles were primarily characterized by several analytical tools to confirm the functionalities, surface texture, crystallinity, and elemental composition. For the investigation of conductive nature, the proposed NiFe2O4/GCE was exploited to the primary electrochemical characterization tools e.g. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The ultra-sensitive determination of PCP was carried out under the linear dynamic range from 0.01 to 90 µM at the pulse amplitude of 80 mV/s in BRB buffer pH of 4. The limit of detection of the developed methods for PCP was calculated to be 0.0016 µM. The analytical applicability of the fabricated sensor was tested in different water samples depicting the acceptable recovery values.

Analysis of challenges faced and the scientific content of a hybrid pediatric surgical conference arranged during the COVID-19 pandemic.

BACKGROUND: Scientific conferences which are considered as an important event for dissemination of research and related academic activities were badly affected during the COVID-19 pandemic. Virtual format for interaction was used as an alternative method to continue such academic discourse. However, this did not provide the same level of communication and interest as that of in-person meetings. With evolving knowledge about the COVID-19 pandemic especially its transmission, role of vaccine, and observing standard operating procedures (SOPs), fear among healthcare providers is mitigated to some extent. Keeping in mind the importance of scientific conferences in the context of sharing knowledge and its impact on the training of faculty members and postgraduate residents, a hybrid conference was planned by the national association of pediatric surgeons.The purpose of this study was to retrospectively review the challenges faced during the organization of this conference as well as to analyze the pattern of registration, number of abstracts received, the gender of the participants and their status, region of the country they represented, type of presentation made, and scientific subject covered. SPSS version 22 was used for data entry. Descriptive and inferential statistics were used to present data. Chi square test was applied to find out the association between categorical variables and a p value < 0.05 was considered as significant. RESULTS: A total of 170 pediatric surgeons and postgraduate residents participated from all over the country and abroad. Nearly half (47.1%) of the registrants were postgraduate residents. Most of the participants (90%) opted for in-person attendance. The venue was selected with a capacity to house more than double the number of registrants with provision of safe distance. Availability of face masks, gloves, and sanitizers was ensured by the organizers. Packed meal boxes were arranged and served at the venue site in an open place on the terrace. A total of 97 abstracts were accepted for presentation that included 57 (58.8%) long oral podium and 40 (41.2%) poster presentations. Most of the studies (n=48-49.4%) were related to the subject of gastroenterology including pancreatico-hepatobiliary system and spleen. Majority of the presenters were male (p = 0.046) and postgraduate residents (p = 0.001). CONCLUSION: It was possible to organize a hybrid annual medical conference where most of the participants preferred physical presence. A rich scientific program was made to cater the needs for pediatric surgical fraternity. Residents made attractive presentations. It was noted that physical presence during clinical conference produced effective communication and learning.

Effect of Strict Lockdown on Pediatric Surgical Services and Residency Programme during COVID-19 Pandemic.

OBJECTIVE: To document the measures adopted during the COVID-19 pandemic strict lockdown on pediatric surgical services and residents' training at a tertiary care hospital. STUDY DESIGN: Cross-sectional descriptive study. PLACE AND DURATION OF STUDY: Department of Pediatric Surgery, National Institute of Child Health, Jinnah Sindh Medical University, Karachi, from April 2020 to June 2020. METHODOLOGY: Data from the Outpatient Department, Emergency Department, and Operation Theatre records were collected. The number of patients seen in the outpatient department, surgeries performed, index emergency cases dealt with, and the residents' duty roster and teaching methodology were documented. Descriptive statistics were used for reporting. RESULTS: During the strict lockdown period, outpatient services continued; however, elective cases were not operated. A total of 2,930 patients were seen in clinics, and 1,316 surgical procedures were performed. The index cases managed included anorectal malformation (n=35), esophageal atresia with and without tracheoesophageal fistula (n=13), small bowel atresia (n=11), omphalocele (n=6), acute appendicitis (n=35), intestinal obstructions (n=23), intussusceptions (n=18), and intestinal perforations (n=16). On-call days of residents were reduced from every third to the fifth day, and online educational sessions were added. During the pandemic, 13 members of surgical and anaesthesia teams got infected with COVID-19. CONCLUSION: COVID-19 pandemic elective surgical services were restricted; however, emergency cases were managed as per routine. In clinical teaching, virtual technologies were incorporated. Working hours of residents were limited to decrease the exposure to infected persons. Key Words: COVID-19, SARS-CoV-2 pandemic, Healthcare workers, Residency programme.

Mathematical Modeling and Analysis of Distributed Energy Systems for a Refinery in Kuwait.

In this study, a model is developed to optimally integrate various energy generation technologies within a refinery to help reduce economic costs as well as mitigate carbon emissions. The combined heat and power system was found to reduce 80 Mton of CO2 emissions while saving $2.61 billion dollars over 30 years as opposed to utilizing boilers and grid-connected electricity. Maximum carbon emissions can be prevented by installing wind turbines to reduce further 49 Mton of carbon emissions, saving at an added cost of $53.4 million. Purchasing electricity completely from the grid was found to be the most expensive option, resulting in a monthly average of $25 million. Changes in various factors such as the land available for installation of technology, electricity tariffs, and efficiency of modules and their impacts on the total project costs and emissions were studied. It was found that solar photovoltaic (PV) modules can be a more economical and environmentally friendly option than wind technology if they were equally efficient. Moreover, grid-connected electricity would only be the most economical option if it were purchased at $0.03/kWh or lower. However, it is currently sold at close to $0.10/kWh, making CHP the most economic option for refineries.

A Molecular Simulation Study of Silica/Polysulfone Mixed Matrix Membrane for Mixed Gas Separation.

Polysulfone-based mixed matrix membranes (MMMs) incorporated with silica nanoparticles are a new generation material under ongoing research and development for gas separation. However, the attributes of a better-performing MMM cannot be precisely studied under experimental conditions. Thus, it requires an atomistic scale study to elucidate the separation performance of silica/polysulfone MMMs. As most of the research work and empirical models for gas transport properties have been limited to pure gas, a computational framework for molecular simulation is required to study the mixed gas transport properties in silica/polysulfone MMMs to reflect real membrane separation. In this work, Monte Carlo (MC) and molecular dynamics (MD) simulations were employed to study the solubility and diffusivity of CO2/CH4 with varying gas concentrations (i.e., 30% CO2/CH4, 50% CO2/CH4, and 70% CO2/CH4) and silica content (i.e., 15-30 wt.%). The accuracy of the simulated structures was validated with published literature, followed by the study of the gas transport properties at 308.15 K and 1 atm. Simulation results concluded an increase in the free volume with an increasing weight percentage of silica. It was also found that pure gas consistently exhibited higher gas transport properties when compared to mixed gas conditions. The results also showed a competitive gas transport performance for mixed gases, which is more apparent when CO2 increases. In this context, an increment in the permeation was observed for mixed gas with increasing gas concentrations (i.e., 70% CO2/CH4 > 50% CO2/CH4 > 30% CO2/CH4). The diffusivity, solubility, and permeability of the mixed gases were consistently increasing until 25 wt.%, followed by a decrease for 30 wt.% of silica. An empirical model based on a parallel resistance approach was developed by incorporating mathematical formulations for solubility and permeability. The model results were compared with simulation results to quantify the effect of mixed gas transport, which showed an 18% and 15% percentage error for the permeability and solubility, respectively, in comparison to the simulation data. This study provides a basis for future understanding of MMMs using molecular simulations and modeling techniques for mixed gas conditions that demonstrate real membrane separation.

Spectrum of Omphalomesenteric Duct Related Anomalies and Their Surgical Management in Children.

Objective The aim of this study was to evaluate the clinical presentation and surgical management of omphalomesenteric duct (OMD) remnants in children.  Material and methods A descriptive retrospective study was conducted at the Department of Paediatric Surgery of the National Institute of Child Health, Karachi, Pakistan, from April 2017 to January 2020. Children below 12 years of age with various OMD remnants were included in the study. Data regarding age of presentation, type of anomaly, and management collected during this period were reviewed and analyzed using SPSS Version 22 (IBM Corp., Armonk, NY, USA). Results A total of 86 patients, 47 males and 39 females, were managed during the study period. Intestinal obstruction was observed in 44 (51.16%) cases followed by OMD-related umbilical anomalies in 14 (16.27%) cases, acute abdominal pain in 12 (13.95%), rectal bleeding in 3 (3.48%) patients. In 13 (15.16%) cases, Meckel's diverticulum was discovered incidentally. In 21 cases, wedge resection and ileal repair was performed, whereas 32 required segmental resection and end-to-end anastomosis, and in 32 cases ileostomy was created after resection. Histopathology showed the presence of ectopic mucosa in five cases. Conclusion Patients with OMD remnants had various presentations. The surgical procedure has to be tailored according to the clinical and surgical findings.

Early Surgical Management of Appendicular Mass in Pediatric Patients.

OBJECTIVE: To find out the feasibility and safety of early surgery in pediatric patients who presented with appendicular mass. STUDY DESIGN: Analytical observational study.  Place and Duration of Study:  Department of Paediatric Surgery, National Institute of Child Health, Jinnah Sindh Medical University, Karachi, from September 2019 to April 2020. METHODOLOGY: This study was conducted on 60 children, who were diagnosed with appendicular mass. Patients were operated after initial stabilisation and investigations. Variables analysed included demographic characteristics, clinical presentation, intraoperative surgical difficulties and postoperative complications. Data were entered into SPSS version 22. Chi-square test and Fisher Exact test were used for finding statistical significance among variables. A p-value of <0.05 was considered as significant.  Results: There were 41 (68.4%) male and 19 (31.6%) female patients with the mean age of 8.3 + 2.9 year. Mean duration of pain was 3.8 + 1.8 days. In 41 (68.4%) patients, mass was composed of appendix with adherent ileal loops and omentum, while in 19 (31.6%) patients frank pus was also found within the mass. Thirty-four (56.6%) patients had suppurative appendix without gross perforation, while in 26 (43.4%) patients partially sloughed / gangrenous perforated appendix found. Intraoperative difficulties were more in patients with complex mass (p=0.004). Postoperative complications were observed in 14 (23.3%) patients. These were more frequent in female patients (p=0.001), with sloughed, gangrenous perforated appendix (p=0.034) and complex mass (p=0.008). Superficial wound infection was the most common complication noted in 9 (15%) patients. In 5 (8.3%) children, deep seated intra-abdominal collections were found. The mean hospital stay was 3.4 + 1.5 days.   Conclusion: Early surgery in pediatric patients with appendicular mass was found feasible with minimal complications. This obviated the need of prolonged follow-up and interval appendectomy with its inherent risks. Key Words: Appendicular mass, Appendicular lump, Appendectomy, Child.

Cervical spine fragility fractures in older people: 5-year experience at a regional spine centre.

BACKGROUND: cervical spine fractures are particularly prevalent in older people and commonly occur following a fall from standing height or less. Atlanto-axial complex (AAC) and, particularly, odontoid process (OP) fractures are the most prevalent injuries. OBJECTIVE: to investigate the incidence and characteristics of cervical spine fractures in older patients presenting to a regional spine centre. METHODS: a retrospective review of the clinical records and imaging of all patients aged 70 years and over presenting to a regional spinal unit with a cervical injury over a 5-year period was performed. Patient demographics, mechanism of injury, level of fracture, stability of the fracture, treatment modality, imaging modality and mortality rates were collected and analysed. RESULTS: during the period between 2015 and 2019, a total of 209 patients aged 70 years and over were presented to the regional spine unit. The mean age at presentation was 82.4 (±7.5) years. Low-energy trauma was the commonest mechanism of injury (n = 169; 80.9%). MRI was undertaken in a quarter of the patients. One-hundred and fifty-one patients (72.2%) suffered an AAC Injury with OP fractures forming the majority of this group (n = 119; 78.8%). One-hundred and ninety-nine patients were treated conservatively, and the overall 30-day mortality rate was 8.1%. CONCLUSION: cervical spine fractures are not uncommon amongst older people and are mostly the result of low-energy trauma and predominantly affect the axial cervical spine. The majority of these injuries are managed conservatively with an orthosis. The fractures nevertheless are a serious injury, with a high mortality rate at 30 days.

Physical property and gas transport studies of ultrathin polysulfone membrane from 298.15 to 328.15 K and 2 to 50 bar: atomistic molecular simulation and empirical modelling.

Elucidation of ultrathin polymeric membrane at the laboratory scale is complicated at different operating conditions due to limitation of instruments to obtain in situ measurement data of membrane physical properties. This is essential since their effects are reversible. In addition, tedious experimental work is required to collect gas transport data at varying operating conditions. Recently, we have proposed a validated Soft Confining Methodology for Ultrathin Films that can be used to simulate ultrathin polysulfone (PSF) membranes upon confinement limited to 308.15 K and 2 bars. In industry application, these ultrathin membranes are operated within 298.15-328.15 K and up to 50 bars. Therefore, our proposed methodology using computational chemistry has been adapted to circumvent limitation in experimental study by simulating ultrathin PSF membranes upon confinement at different operating temperatures (298.15 to 328.15 K) and pressures (2 to 50 bar). The effect of operating parameters towards non-bonded and potential energy, free volume, specific volume and gas transport data (e.g. solubility and diffusivity) for oxygen and nitrogen of the ultrathin films has been simulated and collected using molecular simulation. Our previous empirical equations that have been confined to thickness dependent gas transport properties have been modified to accommodate the effect of operating parameters. The empirical equations are able to provide a good quantitative characterization with R 2 ≥ 0.99 consistently, and are able to be interpolated to predict gas transport properties within the range of operating conditions. The modified empirical model can be utilized in process optimization studies to determine optimal membrane design for typical membrane specifications and operating parameters used in industrial applications.

Synergistic effect on co-pyrolysis of rice husk and sewage sludge by thermal behavior, kinetics, thermodynamic parameters and artificial neural network.

This study investigates the thermal decomposition, thermodynamic and kinetic behavior of rice-husk (R), sewage sludge (S) and their blends during co-pyrolysis using thermogravimetric analysis at a constant heating rate of 20 °C/min. Coats-Redfern integral method is applied to mass loss data by employing seventeen models of five major reaction mechanisms to calculate the kinetics and thermodynamic parameters. Two temperature regions: I (200-400 °C) and II (400-600 °C) are identified and best fitted with different models. Among all models, diffusion models show high activation energy with higher R2(0.99) of rice husk (66.27-82.77 kJ/mol), sewage sludge (52.01-68.01 kJ/mol) and subsequent blends (45.10-65.81 kJ/mol) for region I and for rice husk (7.31-25.84 kJ/mol), sewage sludge (1.85-16.23 kJ/mol) and blends (4.95-16.32 kJ/mol) for region II, respectively. Thermodynamic parameters are calculated using kinetics data to assess the co-pyrolysis process enthalpy, Gibbs-free energy, and change in entropy. Artificial neural network (ANN) models are developed and employed on co-pyrolysis thermal decomposition data to study the reaction mechanism by calculating Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and coefficient of determination (R2). The co-pyrolysis results from a thermal behavior and kinetics perspective are promising and the process is viable to recover organic materials more efficiently.