Performance optimization for an optimal operating condition for a shell and heat exchanger using a multi-objective genetic algorithm approach.

In this study, shell and heat exchangers are optimized using an integrated optimization framework. In this research, A structured Design of Experiments (DOE) comprising 16 trials was first conducted to systematically determine the essential parameters, including mass flow rates (mh, mc), temperatures (T1, t1, T2, t2), and heat transfer coefficients (€, TR, U). By identifying the first four principal components, PCA was able to determine 87.7% of the variance, thereby reducing the dimensionality of the problem. Performance-related aspects of the system are the focus of this approach. Key outcomes (€, TR, U) were predicted by 99% R-squared using the RSM models. Multiple factors, such as the mass flow rate and inlet temperature, were considered during the design process. The maximizing efficiency, thermal resistance, and utility were achieved by considering these factors. By using genetic algorithms, Pareto front solutions that meet the requirements of decision-makers can be found. The combination of the shell and tube heat exchangers produced better results than expected. Engineering and designers can gain practical insight into the mass flow rate, temperature, and key responses (€, TR, U) if they quantify improvements in these factors. Despite the importance of this study, it has several potential limitations, including specific experimental conditions and the need to validate it in other situations as well. Future research could investigate other factors that influence system performance. A holistic optimization framework can improve the design and engineering of heat exchangers in the future. As a result of the study, a foundation for innovative advancements in the field has been laid with tangible improvements. The study exceeded expectations by optimizing shell and heat exchanger systems using an integrated approach, thereby contributing significantly to the advancement of the field.

Recent Advances in the Management of Anal Cancer.

The incidence and mortality of squamous cell carcinoma of the anus (SCCA) is on the rise, which highlights the unmet need for advances in treatment options. The landscape of treatment for this cancer is rapidly evolving with novel combination strategies including immunotherapy, radiation therapy and biomarker-guided therapy. This review article features an overview of recent advancements in both locoregional and metastatic SCCA. The recent focus on locoregional SCCA management is to tailor treatment according to tumor burden and minimize treatment-related toxicities. Mitomycin plus either infusional 5-fluorouracil (5-FU) or capecitabine is used for first-line chemoradiotherapy (CRT), and intensity-modulated radiotherapy (IMRT) is the preferred modality for radiation for locoregional anal cancer. Locally recurrent disease is managed with surgical resection. Systemic treatment is first-line for metastatic SCCA and immunotherapy with nivolumab and pembrolizumab being included as second-line agents. Current and future clinical trials are evaluating treatments for SCCA including immunotherapy alone or in combination regimens, radiotherapies, targeted treatments and novel agents. Another critical aspect of current research in SCCA is the personalization of CRT and immunotherapies based on molecular characterization and biomarkers such as the programmed death-ligand 1 (PD-L1), epidermal growth factor receptor (EGFR) and circulating tumor DNA.

Plasma Epinephrine Contributes to the Development of Experimental Hypoglycemia-Associated Autonomic Failure.

BACKGROUND: Recurrent hypoglycemia blunts counter-regulatory responses to subsequent hypoglycemic episodes, a syndrome known as hypoglycemia-associated autonomic failure (HAAF). Since adrenergic receptor blockade has been reported to prevent HAAF, we investigated whether the hypoglycemia-associated rise in plasma epinephrine contributes to pathophysiology and reported interindividual differences in susceptibility to HAAF. METHODS: To assess the role of hypoglycemia-associated epinephrine responses in the susceptibility to HAAF, 24 adult nondiabetic subjects underwent two 2-hour hyperinsulinemic hypoglycemic clamp studies (nadir 54 mg/dL; 0-2 hours and 4-6 hours) on Day 1, followed by a third identical clamp on Day 2. We challenged an additional 7 subjects with two 2-hour infusions of epinephrine (0.03 µg/kg/min; 0-2 hours and 4-6 hours) vs saline on Day 1 followed by a 200-minute stepped hypoglycemic clamp (90, 80, 70, and 60 mg/dL) on Day 2. RESULTS: Thirteen out of 24 subjects developed HAAF, defined by ≥20% reduction in average epinephrine levels during the final 30 minutes of the third compared with the first hypoglycemic episode (P < 0.001). Average epinephrine levels during the final 30 minutes of the first hypoglycemic episode were 2.3 times higher in subjects who developed HAAF compared with those who did not (P = 0.006).Compared to saline, epinephrine infusion on Day 1 reduced the epinephrine responses by 27% at the 70 and 60 mg/dL glucose steps combined (P = 0.04), with a parallel reduction in hypoglycemic symptoms (P = 0.03) on Day 2. CONCLUSIONS: Increases in plasma epinephrine reproduce key features of HAAF in nondiabetic subjects. Marked interindividual variability in epinephrine responses to hypoglycemia may explain an individual's susceptibility to developing HAAF.

Glycemic management and clinical outcomes in underserved minority kidney transplant recipients with type 2 and posttransplantation diabetes: A single-center retrospective study.

AIMS: Little is known about glycemic management, particularly with novel cardio-nephroprotecive agents, in underserved minority kidney transplant recipients with pre-transplant type 2 (T2DM) and posttransplantation diabetes mellitus (PTDM). We assessed glycemic management and outcomes in this high-risk population. METHODS: We reviewed records of patients who received kidney transplants between June 2012 and December 2014 at a single center. Hemoglobin A1c (HbA1c) and prescribed glucose-lowering medications were examined, and mortality was compared between T2DM, PTDM, and no diabetes (NoDM) patients. RESULTS: We followed 302 patient records (41.1% Hispanic, 41.1% non-Hispanic black) for a median (IQR) of 45.5 (37.0, 53.0) months post-transplant. Pre-transplant T2DM was present in 152 (50.3%), while 58 (19.2%) developed PTDM and 92 (30.4%) remained NoDM. At 1-year post-transplant, the average HbA1c was 8.1 ± 1.8% in T2DM and 6.6 ± 1.3% in PTDM. No glucose-lowering agents were prescribed in 3.4% of T2DM and 44.8% of PTDM. When treated, both received mostly insulin and metformin. Diabetes, HbA1c and insulin therapy were not independently associated with risk of mortality. CONCLUSIONS: Glycemic management was suboptimal and relied on older medications. Further studies are needed to assess longer-term outcomes of more rigorous glycemic management, and the value of novel cardio-nephroprotective agents in kidney transplant recipients.

The paradox prevails: Outcomes are better in critically ill obese patients regardless of the comorbidity burden.

During critical illness, obese patients have better outcomes compared to patients with normal BMI, and this is known as the obesity paradox. The difference in comorbidity burden have been implied to be responsible for the paradox. We performed a retrospective review from 2001 to 2012 of critically ill patients from the Medical Information Mart for Intensive Care database. We included 11,433 patients and classified them according to body mass index (BMI) and comorbidity burden (Elixhauser comorbidity measure). The odds of inpatient mortality were lower in obese patients compared to patients with normal BMI; in group with the least comorbidity score (Elixhauser <0) [OR: 0.47, CI (0.28-0.80), p-value 0.006] and higher comorbidity scores, (Elixhauser 1-5) [(OR: 0.66, CI (0.46-0.95), p-value 0.02)] and (Elixhauser 6-13) [OR: 0.69, CI (0.53-0.92), p-value 0.01]. 30-day mortality was also significantly lower in obese patients, in groups with the lowest (Elixhauser <0) [OR:49, CI (0.31-0.77), p-value 0.002] as well as the highest comorbidity burden (Elixhauser >14) [OR:0.59, CI (0.45-0.77), p-value <.001]. Subgroup analysis in patients with various comorbidities showed better outcomes in obese patients. These findings show that the decreased odds of mortality in critically ill obese patients is independent of the comorbidity burden or type of comorbidity.

Pancreas as an Occult Source of Recurrent Salmonella enteritidis Bacteremia in an Immunocompromised Patient.

Salmonella infection usually presents as gastroenteritis and enteric fever. Some cases of bacteremia can lead to invasion of different organ systems and become occult sources for recurrence. Almost all organs of the body can be affected and have been reported in the literature. We report a rare case of repeated Salmonella enteritidis infection in a patient with systemic lupus erythematosus. She was treated with intravenous and oral antibiotics but still had recurrence of fevers and bacteremia. After a thorough workup, pancreatic abscesses were identified and drained with abscess culture revealing Salmonella enteritidis. She was then treated with a prolonged course of antibiotics and finally cleared the infection. This case demonstrates that nontyphoid Salmonella can be invasive and cause persistent infection. This is particularly pertinent in immunocompromised patients who are at an increased risk of infection. An aggressive workup and prolonged antibiotic course might be beneficial for this subset of patients.

Comparative Study of Serum Lipid Profiles in Nepalese Cancer Patients Attending a Tertiary Care Hospital

Significant efforts have been made to study cancer at the biochemical and cellular level and identify factors associated with progression. The aim of this hospital based randomized comparative study at the Nepalese Army Institute of Health science hospital was to assess factors in 52 people diagnosed with different types of cancer and 56 normal control persons. Fasting blood samples were analyzed for serum total cholesterol (TC), high density lipoprotein (HDL), triglycerides (TG) and low density lipoprotein (LDL). We found that biochemical parameter TC, TG, VLDL (very low density lipoprotein), LDL and HDL were significantly different in the cancer patients and healthy controls. Levels of TC, TG, LDL, HDL and VLDL were higher in the age group below 50 and that of TG was found to be higher in women than men. Our results indicate that TC, TG and HDL are increased, while LDL and VLDL are lowered in cancer patients. Our study provides clues to risk factors associated with life style, eating habits, and exercise regimens. Monitoring of these parameters with aging is recommended.