Analysis of Veno-Venous Extracorporeal Membrane Oxygenation for COVID-19 Compared to Non-COVID Etiologies.

OBJECTIVE: This study analyzed the characteristics and outcomes of veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) due to COVID-19 versus non-COVID causes at US academic centers. BACKGROUND DATA: V-V ECMO support has been utilized for COVID-19 patients with ARDS since the beginning of the pandemic. Mortality for ECMO in COVID-19 has been reported to be high but similar to reported mortality for ECMO support for non-COVID causes of respiratory failure. METHODS: Using ICD-10 codes, data of patients who underwent V-V ECMO for COVID-19 ARDS were compared with patients who underwent V-V ECMO for non-COVID causes between April 2020 and December 2022. The primary outcome was in-hospital mortality. Secondary outcome measures included length of stay and direct cost. Multivariate logistic regression modeling was performed to analyze differences in mortality between COVID and non-COVID groups, adjusting for other important risk factors (age, sex, and race/ethnicity). RESULTS: We identified and compared 6382 patients who underwent V-V ECMO for non-COVID causes to 6040 patients who underwent V-V ECMO for COVID-19. There was a significantly higher proportion of patients aged ≥ 65 years who underwent V-V ECMO in the non-COVID group compared with the COVID group (19.8% vs. 3.7%, respectively, P <0.001). Compared with patients who underwent V-V ECMO for non-COVID causes, patients who underwent V-V ECMO for COVID had increased in-hospital mortality (47.6% vs. 34.5%, P <0.001), length of stay (46.5±41.1 days vs. 40.6±46.1, P <0.001), and direct hospitalization cost ($207,022±$208,842 vs. $198,508±205,510, P =0.02). Compared with the non-COVID group, the adjusted odds ratio (OR) for in-hospital mortality in the COVID group was 2.03 (95% CI: 1.87-2.20, P <0.001). In-hospital mortality for V-V ECMO in COVID-19 improved during the study time period (50.3% in 2020, 48.6% in 2021, and 37.3% in 2022). However, there was a precipitous drop in the ECMO case volume for COVID starting in quarter 2 of 2022. CONCLUSIONS: In this nationwide analysis, COVID-19 patients with ARDS requiring V-V ECMO support had increased mortality compared with patients who underwent V-V ECMO for non-COVID etiologies.

Lead analysis by µSPE/FF-AAS: A comparative study based on dimethylglyoxime functionalized silica-coated magnetic iron/graphene oxides.

Here, four new sorbents based on dimethylglyoxime (DMG) functionalized silica-coated magnetic iron/graphene oxides (Fe3O4/MGO) were synthesized. A comparative study was performed among them to evaluate the different substrates and the role of the spacer in improving the lead extraction efficiency and selecting the most efficient sorbent. Based on experimental results, MGO@SiO2@3-chloropropyltrimethoxysilane@DMG was selected for magnetic dispersive µSPE of lead followed by flame (FAAS) and graphite furnace atomic absorption spectroscopy (GFAAS). The sorbents were characterized by FT-IR, FE-SEM, EDX, TEM, and Zeta potential. Sorbent amount (40.5 mg), sample pH (7.7), sonication time of adsorption and desorption procedures (9 min), and volume and acid concentration (2.2 mL of 2.7 mol L-1 nitric acid) were optimized using experimental design. Linearity of 20.0-600.0 ng mL-1 and 0.5-3.0 ng mL-1 resulted by FAAS and GFAAS, respectively. LODs were 7.0 and 0.2 ng mL-1 by FAAS and GFAAS, respectively. Intra- and inter-day RSDs% (n = 3) at two concentration levels of 3.0 and 100.0 ng mL-1 were below 7.6%.The adsorption capacity was 45.05 mg g-1. The adsorption isotherm showed a better fitting with the Langmuir model. Relative recoveries (%) of 87.8-115.1% were obtained for measuring trace amounts of lead in water, hair, and nail samples.

Pipette-tip SPE based on Graphene/ZnCr LDH for Pb(II) analysis in hair samples followed by GFAAS.

In this work, a nanocomposite of ZnCr layered double hydroxide (ZnCr LDH) and graphene oxide (GO) was successfully assembled. An efficient pipette-tip solid-phase extraction (PT-SPE) based on GO/ZnCr LDH followed by GFAAS analysis was used for to preconcentrate Pb(II) in hair samples. Hair samples were treated using acid digestion to make the solid samples suitable for performing the PT-SPE procedure and decrease the interactions between Pb(II) ions and the sample matrix. The sorbent was characterized by FT-IR, SEM, TEM, EDX, elemental mapping, and XRD. Effective extraction parameters were thoroughly investigated. Under the best conditions, the calibration plot was linear within the range of 0.5-15 ng mL-1 (R2 = 0.991). Preconcentration factor (PF) of 10 and absolute recovery (%) of 100% were obtained. LOD and LOQ were found to be 0.1 µg g-1 and 0.5 µg g-1, respectively. The intra-day and inter-day precisions (n = 3) at the concentrations of 2.0 and 10 ng mL-1 were less than 6.8% and 12.5%, respectively. Finally, the method efficiency was investigated for the analysis of Pb(II) in hair samples, and good relative recoveries (RR%) were obtained within the range of 92%-104%.

Venous thromboembolism risk for the contemporary bariatric surgeon.

BACKGROUND: Postoperative venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), are the leading causes of morbidity and mortality after bariatric surgery. Although several studies have examined VTE, few have examined risk factors separately for DVT and PE after contemporary bariatric surgery, including laparoscopic sleeve gastrectomy (LSG). Our objective was to define risk factors for DVT and PE independently for both LSG and laparoscopic Roux-en-Y gastric bypass (LRYGB) patients using the largest validated bariatric surgery database. METHODS: The metabolic and bariatric surgery accreditation and quality improvement program (MBSAQIP) database was queried to identify patients who underwent LSG or LRYGB between January 2015 and December 2017. Perioperative data were compared using bivariate analysis. Risk of DVT and PE after LSG or LRYGB was determined using multivariable logistic regression analysis. RESULTS: During the study period, 369,032 bariatric cases (72% LSG, 28% LRYGB) were performed. The incidence of DVT was similar between LSG and LRYGB (0.2% vs. 0.2%, p = 0.96), while the incidence of PE was decreased for LSG compared to LRYGB (0.1% vs. 0.2%, p < 0.001). Operative length was associated with increased risk of postoperative DVT (OR 1.1, CI 1.01-1.30, p = 0.04) and postoperative PE (OR 1.4, CI 1.16-1.64, p < 0.001) after surgery. The largest independent risk factors for DVT were history of DVT (OR 6.2, CI 4.44-8.45, p < 0.001) and transfusion (OR 4.2, CI 2.48-6.63, p < 0.001). The largest independent risk factors for PE were transfusion (OR 5.0, CI 2.69-8.36, p < 0.001) and history of DVT (OR 2.8, CI 1.67-4.58, p < 0.001). LSG was associated with a decreased risk of PE compared to LRYGB (OR 0.7 CI 0.55-0.91, p = 0.01). CONCLUSIONS: Prolonged operative length is associated with a higher risk of DVT and PE after either LSG or LRYGB. Transfusion and history of DVT are the largest risk factors for developing DVT and PE. There is a decreased risk of PE after LSG compared to LRYGB.

Renal effects of general anesthesia from old to recent studies.

Various types of anesthesia are being utilized to maintain physiologically secured surgical conditions. Nearly all categories of general anesthesia are characterized by various perioperative and postoperative complications. These shortcomings are important aspects that need to be considered by the anesthesiologist and surgeon before administration of these compounds. The renal effects of anesthesia play an important role in understanding possible systemic changes due to the fact that the kidney has a direct or indirect impact on nearly all the systems of the body. Various studies have been conducted to find out changes in renal parameters and its systemic effects upon administration of the anesthesia and its postoperative repercussions. Besides that, the impaired renal function might have an impact on the excretion of anesthetic metabolites, which can lead to long-term dysfunction. Patients with a previous history of disease ought to be brought under consideration because these chemicals can ameliorate pre-existent symptoms. This review is intended to discuss the early and latest studies based on the effects of general anesthesia on the renal system.

Renal impairment and analgesia: From effectiveness to adverse effects.

Kidney pain is one of the clinically significant features of renal dysfunction. Mild to severe pain is seen in the lower back area. Painkillers are mostly recommended in these cases to relieve the symptom. Yet, several analgesics are associated with side effects that can worsen the state of the disease. This review is based on the studies conducted in these aspects analgesics used to treat kidney pain and their effectiveness, renal consequences of postoperative analgesia, and pharmacogenetics of these palliatives are briefly summarized in this paper.

High and low estimated glomerular filtration rates are associated with adverse outcomes in patients undergoing surgery for gastrointestinal malignancies.

BACKGROUND: Abnormally high estimated glomerular filtration rates (eGFRs) are associated with endothelial dysfunction and frailty. Previous studies have shown that low eGFR is associated with increased morbidity, but few reports address high eGFR. The purpose of this study is to evaluate the association of high eGFR with surgical outcomes in patients undergoing surgery for gastrointestinal malignancies. METHODS: We identified patients who underwent elective surgery for gastrointestinal malignancies from 2005 to 2015 in the American College of Surgeons National Surgical Quality Improvement Program database. We evaluated associations of eGFR with surgical outcomes by Cox or logistic models with restricted cubic spline functions, adjusting for case mix variables (i.e. age, gender, race and diabetes). RESULTS: The median eGFR is 83 (interquartile range 67-96) mL/min/1.73 m2. Thirty-day mortality was 1.9% (2555/136 896). There is a U-shaped relationship between eGFR and 30-day mortality. The adjusted hazard ratios (95% confidence intervals) for eGFRs of 30, 60, 105 and 120 mL/min/1.73 m2 (versus 90 mL/min/1.73 m2) are 1.73 (1.52-1.97), 1.00 (0.89-1.11), 1.42 (1.31-1.55) and 2.20 (1.79-2.70), respectively. Similar associations are shown for other surgical outcomes, including return to the operating room and postoperative pneumonia. Subgroup analyses show that eGFRs both higher and lower than the respective medians are consistently associated with a higher risk of adverse outcomes across age, gender and race. CONCLUSIONS: High and low eGFRs are associated with more adverse surgical outcomes in patients undergoing surgery for gastrointestinal malignancies. The eGFR associated with the lowest postoperative risk is approximately at the median eGFR of a given population.

Robotic versus laparoscopic sleeve gastrectomy: a MBSAQIP analysis.

BACKGROUND: Laparoscopic sleeve gastrectomy has become the procedure of choice for the treatment of morbid obesity. Robotic sleeve gastrectomy is an alternative surgical option, but its utilization has been low. The aim of this study was to evaluate the contemporary outcomes of robotic sleeve gastrectomy (RSG) versus laparoscopic sleeve gastrectomy (LSG) using a national database from accredited bariatric centers. STUDY DESIGN: Using the 2015 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database, clinical data for patients who underwent RSG or LSG were examined. Emergent and revisional cases were excluded. A multivariate logistic regression model was utilized to compare the outcomes between RSG and LSG. RESULTS: A total of 75,079 patients underwent sleeve gastrectomy with 70,298 (93.6%) LSG and 4781 (6.4%) RSG. Preoperative sleep apnea and hypoalbumenia were significantly higher in the RSG group (P < 0.01). Mean length of stay was similar between RSG and LSG (1.8 ± 2.0 vs. 1.7 ± 2.0 days, P = 0.17). Operative time was longer in the RSG group (102 ± 43 vs. 74 ± 36 min, P < 0.01). There was no significant difference in 30-day mortality between the RSG versus LSG group (0.02% vs. 0.01%, AOR 0.85; 95% CI 0.11-6.46, P = 0.88). However, RSG was associated with higher serious morbidity (1.1% vs. 0.8%, AOR 1.40; 95% CI 1.05-1.86, P < 0.01), higher leak rate (1.5% vs. 0.5%, AOR 3.14; 95% CI 2.65-4.42, P < 0.01), and higher surgical site infection rate (0.7% vs. 0.4%, AOR 1.55; 95% CI 1.08-2.23, P = 0.01). CONCLUSIONS: Robotic sleeve gastrectomy has longer operative time and is associated with higher postoperative morbidity including leak and surgical site infections. Laparoscopy should continue to be the surgical approach of choice for sleeve gastrectomy.

Respiratory complications after colonic procedures in chronic obstructive pulmonary disease: does laparoscopy offer a benefit?

BACKGROUND: Patients with severe chronic obstructive pulmonary disease (COPD) are at a higher risk for postoperative respiratory complications. Despite the benefits of a minimally invasive approach, laparoscopic pneumoperitoneum can substantially reduce functional residual capacity and raise alveolar dead space, potentially increasing the risk of respiratory failure which may be poorly tolerated by COPD patients. This raises controversy as to whether open techniques should be preferentially employed in this population. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2011 to 2014 was used to examine the clinical data from patients with COPD who electively underwent laparoscopic and open colectomy. Patients defined as having COPD demonstrated either functional disability, chronic use of bronchodilators, prior COPD-related hospitalization, or reduced forced expiratory reserve volumes on lung testing (FEV1 <75%). Demographic data and preoperative characteristics were compared. Linear and logistic regressions were utilized to perform multivariate analysis and determine risk-adjusted outcomes. RESULTS: Of the 4397 patients with COPD, 53.8% underwent laparoscopic colectomy (LC) while 46.2% underwent open colectomy (OC). The LC and OC groups were similar with respect to demographic data and preoperative comorbidities. Equivalent frequencies of exertional dyspnea (LC 35.4 vs OC 37.7%, P = 0.11) were noted. After multivariate risk adjustment, OC demonstrated an increased rate of overall respiratory complications including pneumonia, reintubation, and prolonged ventilator dependency when compared to LC (OR 1.60, 95% CI 1.30-1.98, P < 0.01). OC was associated with longer length of stay (10 ± 8 vs. 6.7 ± 7 days, P < 0.01) and higher readmission (OR 1.36, 95% CI 1.09-1.68, P < 0.01) compared to LC. CONCLUSION: Despite the potential risks of laparoscopic pneumoperitoneum in the susceptible COPD population, a minimally invasive approach was associated with lower risk of postoperative respiratory complications, shorter length of stay, and decrease in postoperative morbidity.

A silica fiber coated with a ZnO-graphene oxide nanocomposite with high specific surface for use in solid phase microextraction of the antiepileptic drugs diazepam and oxazepam.

A novel ZnO-graphene oxide nanocomposite was prepared and is shown to be a viable coating on fused silica fibers for use in solid phase microextraction (SPME) of diazepam and oxazepam from urine, this followed by thermal desorption and gas chromatographic quantitation using a flame ionization detector. A central composite design was used to optimize extraction time, salt percentage, sample pH and desorption time. Limits of detection are 0.5 µg·L-1 for diazepam and 1.0 µg·L-1 for oxazepam. Repeatability and reproducibility for one fiber (n = 4), expressed as the relative standard deviation at a concentration of 50 µg·L-1, are 8.3 and 11.3% for diazepam, and 6.7 and 10.1% for oxazepam. The fiber-to-fiber reproducibility is <17.6%. The calibration plots are linear in the 5.0-1000 µg·L-1 diazepam concentration range, and from 1.0-1000 µg·L-1 in case of oxazepam. The fiber for SPME has high chemical and thermal stability (even at 280 °C) after 50 extractions, and does not suffer from a reduction in the sorption capacity. Graphical abstract A hydrothermal method was introduced for preparation of ZnO- GO nano composite on a fused silica fiber as solid phase microextraction with high mechanical, chemical stability and long service life.

Polypyrrole coated ZnO nanorods on platinum wire for solid-phase microextraction of amitraz and teflubenzuron pesticides prior to quantitation by GC-MS.

The authors describe a new sorbent for amitraz and teflubenzuron pesticides. It consists of a platinum wire coated with polypyrrole-coated ZnO nanorods. The nanocomposite was prepared by a two-step process. In the first step, oriented ZnO nanorods were hydrothermally grown in situ on a platinum wire. Subsequently, oxidative vapor phase polymerization of pyrrole was performed on FeCl3-impregnated ZnO nanorods to give a porous polypyrrole film. The organic/inorganic nanocomposite synthesized through hydrothermal deposition and chemical vapor deposition polymerization yields material with attractive properties. The coated wire was applied to solid-phase microextraction of amitraz (in the form of 2,4-dimethylaniline resulting from the hydrolysis of amitraz) and teflubenzuron. The effects of extraction temperature, extraction time, sample pH value and salt concentration were optimized. The analytes 2,4-dimethylaniline and teflubenzuron were then quantified by GC-MS. Under optimum conditions, the LODs range between 0.1 and 0.15 ng.mL-1. Relative standard deviations at two concentration are <8.3% for intraday precision and <10.3% for inter-day precision. In all cases, the fiber to fiber reproducibility is <12.2%. For both analytes the linear dynamic ranges are 0.5-300 ng.mL-1. The procedure was successfully applied to the analysis of spiked agricultural water samples. Graphical abstract A novel inorganic/organic hybrid nanocomposite was synthesized through in situ hydrothermal deposition of ZnO nanorods and ten placing a thin layer of polypyrrole on them by chemical vapor deposition polymerization. This nanocomposite was applied to fabricate a solid-phase microextraction fiber for the extraction of amitraz and teflubenzuron pesticides residue from agricultural samples prior to their quantitation by GC-MS.

Endothelial cell changes after photorefractive keratectomy with graded usage of mitomycin C.

PURPOSE: To compare differences in the endothelial cells before and after photorefractive keratectomy (PRK) for myopia with refractive error graded mitomycin C (MMC) application. METHODS: In a prospective randomized clinical trial, forty-eight myopic patients referred to Khatam-al-Anbia Eye Hospital, Mashhad, Iran, for PRK. Patients were treated with PRK by a Bausch and Lomb Technolas 217z excimer laser (Bausch and Lomb, Rochester, NY). MMC was applied after PRK 5 s for each diopter of spherical equivalent myopic refractive error corrected. The manifest refraction, visual acuity, MMC treatment length, corneal pachymetry and specular microscopy were evaluated preoperatively and at 1 and 6 months postoperatively. RESULTS: A total of 48 cases (96 eyes, 68.75% female) were treated, with a mean age of 26.70 ± 4.89 years (range, 18-34 years). Postoperative cell density, cell size and polymegathism did not significantly change. On the other hand, standard deviation (SD) of cell size (P = 0.008), pleomorphism (P = 0.003) and coefficient of variation (CV) (P = 0.016) were significantly increased. None of these parameters was related to the length of MMC application. Corneal thickness decreased significantly after the operation but it increased 6 months postoperatively compared with the first month (P < 0.001). CONCLUSION: MMC application for PRK in myopia can affect the endothelial cells, but in early follow-ups, it does not affect the cell density or size. Cell size was changed but it was obvious not in mean cell size, but in SD and CV. MMC time below the 30 s was not significant on endothelial cell changes.

Comparison of autologous fibrin glue versus nylon sutures for securing conjunctival autografting in pterygium surgery.

PURPOSE: To compare the safety, operating time, postoperative ocular signs, symptoms, overall patient satisfaction, complications rate and recurrence rate of autologous fibrin glue (AFG) and nylon suturing (NS) for attaching conjunctival autografts in pterygium surgery. METHODS: A prospective, randomized, interventional study was performed among 120 patients (120 eyes) with primary pterygium. Superior conjunctival autograft was harvested and transferred on to bare sclera after pterygium excision. For attaching the autograft, AFG (n = 60 eyes) and NS (n = 60 eyes) were used. The patients were followed up for 12 months. The groups were compared for the safety, operative time, postoperative ocular signs, symptoms, overall patient satisfaction, recurrence and complications rate. RESULTS: All conjunctival autografts in both groups were successfully attached. The average operating time for the AFG group was significantly shorter (P < 0.001). Postoperative symptoms were fewer for the AFG group than the suture group. After 12 months of follow-up, no recurrence was reported for the AFG group, but 8.3% of patients experienced recurrence in the NS group. CONCLUSIONS: Our study demonstrated the superiority of AFG to NS in saving operating time and elimination of recurrence without any complications in pterygium surgery. AFG can obviate the need for suturing and increases the viability of tissue flaps. Additional studies are necessary to determine the long-term effects considering factors such as primary or recurrent status of pterygium, age and sex of patient, dose and duration of treatment for mitomycin C.

Localized surface plasmon resonance based gold nanobiosensor: Determination of thyroid stimulating hormone.

An immunoassay method based on the peak shift of the localized surface plasmon resonance (LSPR) absorption maxima has been developed for the determination of the thyroid stimulating hormone (TSH) in human blood serum. The anti-TSH antibody was adsorbed on the synthesized gold nanoparticles by electrostatic forces. The efficiency of the nanobiosensor was improved by optimizing the factors affecting the probe construction such as the pH and the antibody to gold nanoparticles ratio. Dynamic light scattering was applied for the characterization of the constructed probe. The amount of peak shift of the LSPR absorption maxima was selected as the basis for determination of TSH antigen. The linear dynamic range of 0.4-12.5 mIU L-1 and the calibration sensitivity of 1.71 L mIU-1 were obtained. The human control serum sample was analyzed for TSH by constructed nanobiosensor and the acceptable results were obtained.

Zinc oxide-copper oxide nanoplates composite as coating for solid phase microextraction combined with high performance liquid chromatography-UV detection for trace analysis of chlorophenols in water and tomato juice samples.

In the present research, the ZnO-CuO nanoplate composite (ZCNC), solid-phase microextraction (SPME) fiber coating, was prepared and its extraction capability for certain chlorophenols (CPs) was studied through directly sampling the typical CPs mixed standard solution of 4-chlorophenol, 2,3-dichlorophenol, 2,5-dichlorophenol, and 2,4,6-trichlorophenol with high performance liquid chromatography. ZCNC thickness was in the range of 50-65 nm. The effective variables on ZCNC-SPME extraction efficiency were extraction time, salt percentage, and desorption time. Accordingly, a multivariate strategy was applied based on an experimental design by using central composite design for optimizing the significant factors affecting the extraction efficiency. The detection limit and relative standard deviation (RSD) (n = 6), that include repeatability and reproducibility as the target analytes, were in the range of 0.5-5 ng ml(-1) and 5.1-14 % of standard solutions at 50 ng ml(-1) concentration of CPs, respectively. The developed technique is believed to be successfully applicable to preconcentration and determination of target analytes in environmental water and tomato juice samples. Graphical Abstract Application of zinc oxide-copper oxide nanoplates composite for extraction of chlorophenols in water and tomato juice samples and optimizing condition by experimental design method.

Trends in colorectal cancer admissions and stage at presentation: impact of screening.

BACKGROUND: Colorectal cancer (CRC) incidence is rising among patients under age 50. As such, we set out to determine the proportion of CRC-related hospital admissions and distribution of colon cancer by stage in different age groups. METHODS: The NIS database for 2002-2012 was used to investigate trends of colorectal cancer resection by age, and the ACS NSQIP database for 2012-2013 was used to investigate contemporary stage at diagnosis for colon cancer in different age groups. RESULTS: A total of 1,198,421 patients were admitted to a hospital with a diagnosis of CRC and captured by the NIS database. Although the number of hospitalized CRC patients decreased from 2002 to 2012, the observed decrease was predominant in patients older than 65 years (P < 0.01) and in colon cancer compared to rectal cancer patients (P < 0.01). The proportion of patients younger than 65 years increased from 32.8 % in 2002 to 41.1 % in 2012, and the proportion of patients under age 50 increased from 9 to 12 %. In the NSQIP database, the age <50 group also had a significantly higher proportion of advanced disease (stage III/IV) compared to patients age 50 and older (62.3 vs. 47.5 %, P < 0.01). In 2012, it was observed that most patients with rectal cancer were younger than 65 years (55.8 %). CONCLUSION: There was a steady decrease in the number of hospitalized patients with colorectal cancer during the last decade, primarily attributable to a decrease in the older than 65 years age patients and colon cancer patients. The proportion of hospitalized patients age <50 is rising. In addition, patients younger than 50 years were more likely to have advanced disease compared to older patients.

Post-Hospital Discharge Venous Thromboembolism in Colorectal Surgery.

BACKGROUND: There are limited data regarding the criteria for prophylactic treatment of venous thromboembolism (VTE) after hospital discharge. We sought to identify risk factors of post-hospital discharge VTE events following colorectal surgery. METHODS: The NSQIP database was utilized to examine patients developed VTE after hospital discharge following colorectal surgery during 2005-2013. Multivariate analysis using logistic regression was performed to quantify risk factors of VTE after discharge. RESULTS: We evaluated a total of 219,477 patients underwent colorectal resections. The overall incidence of VTE was 2.1 % (4556). 33.8 % (1541) of all VTE events occurred after hospital discharge. The length of postoperative hospitalization had a strong association with post-discharge VTE, with the highest risk in patients who were hospitalized for more than 1 week after operation (AOR 9.08, P < 0.01). Other factors associated with post-discharge VTE included chronic steroid use (AOR 1.81, P < 0.01), stage 4 colorectal cancer (AOR 1.40, P = 0.03), obesity (AOR 1.37, P < 0.01), age >70 (AOR 1.21, P = 0.04), and open surgery (AOR 1.36, P < 0.01). Patients who were hospitalized for more than 1 week after an open colorectal resections had a 12 times higher risk of post-discharge VTE event compared to patients hospitalized less than 4 days after a laparoscopic resection (AOR 12.34, P < 0.01). CONCLUSIONS: VTE is uncommon following colorectal resections; however, a significant proportion occurs after patients are discharged from the hospital (33.8 %). The length of postoperative hospitalization appears to have a strong association with post-discharge VTE. High-risk patients may benefit from continued VTE prophylaxis after discharge.

Synthesis of Depo-Medrol-chitosan hydrogel as new drug slow-release appliance and investigation of release kinetics by high-performance liquid chromatography.

The present study deals with preparation and optimization of a novel chitosan hydrogel-based matrix by suspension cross-linking method for controlled release of Depo-Medrol. The controlled release of Depo-Medrol for effective Rheumatoid arthritis disease has become an imperative field in the drug delivery system. In this context, it was intended to optimize loading circumstances by experimental design and also study the release kinetics of Depo-Medrol entrapped in the chitosan matrix in order to obtain maximal efficiency for drug loading. The optimum concentrations of chitosan (2.5 g), glutaraldehyde (3.05 µL) and Depo-Medrol (0.1 mg) were set up to achieve the highest value of drug loaded and the most sustained release from the chitosan matrix. In vitro monitoring of drug release kinetic using high-performance liquid chromatography showed that 73% of the Depo-Medrol was released within 120 min, whereas remained drug was released during the next 67 h. High correlation between first-order and Higuchi's kinetic models indicates a controlled diffusion of Depo-Medrol through the surrounding media. Moreover, recovery capacity >82% and entrapment efficiency of 58-88% were achieved under optimal conditions. Therefore, the new synthesized Depo Medrol-chitosan is an applicable appliance for arthritis therapy by slow release mechanism. Copyright © 2016 John Wiley & Sons, Ltd.

Synthesis of ZnO nanorods and their application in the construction of a nanostructure-based electrochemical sensor for determination of levodopa in the presence of carbidopa.

A novel carbon paste electrode modified with ZnO nanorods and 5-(4'-amino-3'-hydroxy-biphenyl-4-yl)-acrylic acid (3,4'-AAZCPE) was fabricated. The electrochemical study of the modified electrode, as well as its efficiency for the electrocatalytic oxidation of levodopa, is described. The electrode was employed to study the electrocatalytic oxidation of levodopa, using cyclic voltammetry (CV), chronoamperometry (CHA), and square-wave voltammetry (SWV) as diagnostic techniques. It has been found that the oxidation of levodopa at the surface of the modified electrode occurs at a potential of about 370 mV less positive than that of an unmodified carbon paste electrode. The SWV results exhibit a linear dynamic range from 1.0 × 10(-7) M to 7.0 × 10(-5) M and a detection limit of 3.5 × 10(-8) M for levodopa. In addition, this modified electrode was used for the simultaneous determination of levodopa and carbidopa. Finally, the modified electrode was used for the determination of levodopa and carbidopa in some real samples.

Zinc oxide-aluminum oxide nanocomposite solid phase microextraction for diazepam and oxazepam trace determination.

A new efficient ZnO-Al2O3 nanocomposite (ZANC) was synthesized to form solid-phase microextraction (SPME) fiber. The prepared fiber was used for trace determination of benzodiazepines by gas chromatography-flame ionization detector in urine samples. The effective parameters on the extraction process including extraction time, salt percentage, desorption time and sample pH were optimized by a factorial design method. The method was evaluated at the optimum conditions and limits of detection (LODs) were calculated 20 µg/L for diazepam and oxazepam. The method repeatability for oxazepam and diazepam (50 µg/L, n = 4) was calculated at 8.8 % and 6.4 %. Also, the method reproducibility was obtained, 7.45 % and 6.61 % for oxazepam and diazepam (50 µg/L, n = 4). Also, fiber-to-fiber relative standard deviation (RSDs%) for the target analytes were less than 15.5 %. The method linearity is within the range of 62-500 µg/L for diazepam and oxazepam. The ZANC-SPME fiber showed a good lifetime (60 times) with high chemical stability. The high thermal stability of ZANC-SPME fiber was attained at 280 °C. The extraction results of poly dimethylsiloxan/divinyl benzene (PDMS/DVB) fiber were compared by ZANC-SPME fiber. Therefore, the method is proposed as a suitable technique for benzodiazepines detection in the urine sample.