Development of novel formulations to enhance in vivo transdermal permeation of tocopherol

Tocopherol represents a big challenge for transdermal permeation owing to its extreme hydrophobicity and large molecular mass. The aim of the present study was to develop alpha-tocopherol (T) topical formulations and evaluate the ex vivo and in vivo permeation. Franz diffusion cells were used for the ex vivo permeation, and neonatal rats were used for in vivo permeation. Seven gel formulations and 21 liquid formulations were investigated for physical stability, viscosity and permeation of T. Analysis of T was performed by a validated HPLC method using a UV detector.The ex vivo permeation from gel and emulsion formulations was very poor (0.001–0.015 %). The highest permeation was observed from monophasic liquid formulations containing dimethyl sulfuxide (DMSO), tocopheryl polyethylene glycols (TPGs), propylene glycol, ethanol, and 9.5 % T. The in vivo results demonstrated higher retention in the epidermis compared to subcutaneous tissues; 1377 and 1.13 µg g–1, respectively. Increasing T concentration from 4.8 to 9.5 % did not increase the amount permeated or % of T retained. It was concluded that simple solutions of T in presence of DMSO and TPGs are more promising systems for effective transdermal permeation; compared to gel, emulsion or oleaginous systems

Pelvic ring fractures: External fixation comparative numerical structural analysis

External fixation (EF) is commonly practiced for pelvic ring fractures management. Many parameters influence mechanical performances of external fixators. Our virtual 3D model of the pelvic ring introduces the advantage of differentiating the mechanical properties of cortical and cancellous bone along with the complex boundary conditions of major ligaments. We assessed stiffness variations by increasing fixator pins depth and we evaluated dislocation related to load intensity and sitting angle

Single Step Electrodeposited Kesterite Cu2ZnSnS4 (CZTS) thin films at low annealing temperatures

[EN] This paper reports onthe growth of quaternary Cu2ZnSnS4 (CZTS) thin films by a single step electrochemicaldeposition followed by annealing at low temperature.The influence of different annealing atmospheres at constant annealingtimes (t = 45min) and fixed preparation controlling parameters; i.e., starting materials (precursor metal salts) solution concentration, time of deposition and electrodeposition potential. Structural, compositional, morphological, andoptical properties, as well as photoelectrochemical properties were studied. The films, sulfurized during 2 hours, showeda prominent kesterite phase with a nearly stoichiometric composition. Samples were characterizedby X-ray diffraction (XRD), scanning electron microscopy (SEM), EDS and UV-VIS-NIR spectrometry. X-ray diffraction and confirmed the formation of pure kesterite CZTS films. SEM shows that films are compact with densemorphology and homogeneous distribution. EDS analyzed the elemental constituents of the quaternary Cu2ZnSnS4 with an apparent Cu deficiency and S rich for the sulfurized samples. From optical study, the energy gap was indexed for the sulfurized samples,Eg=1.52 eV. Under illumination sulfurized CZTS films exhibits negative photocurrent and positive photovoltagevalues confirming the p-type character of the films.This work was supported by the Culture, Affairs and Missions Sector, Ministry of Higher Education and Scientific Research (Egypt) and Ministerio de Economia y Competitividad (Spain) (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Marí, B.; Mollar García, MA.; El Nahrawy, A.; Saber, S.; Khattab, N.; Eid, A.; Abo-Aly, M.... (2018). Single Step Electrodeposited Kesterite Cu2ZnSnS4 (CZTS) thin films at low annealing temperatures. Insights in Analytical Electrochemistry. 4(1:8):1-6. https://doi.org/10.21767/2470-9867.100028S1641:

Design of a self-tunable, variable-length pendulum for harvesting energy from rotational motion

In this paper, a self-tunable energy harvester based on pendulum oscillations with a mechanical motion rectifier (MMR) system, which can convert vibration into electrical energy, is proposed. The harvester is composed of a pendulum excited by a slider-crank mechanism. The pendulum system is designed to automatically adjust its own natural frequency to match that of the imposed base excitation. Frequency adjustment in a proposed pendulum-type energy harvester is achieved by varying the length of the pendulum rod through changing the position of pendulum mass which mounted at its tip. The pendulum mass is driven by a ball screw through a stepper motor which controls the length of the pendulum automatically in accordance with the frequency of the external motion. The base motion frequency is detected by an infrared sensor. An ultrasonic distance sensor is used to detect the length of the pendulum rod and feeds this information to a microcontroller to obtain the corresponding natural frequency from a lookup table. The microcontroller calculates the frequency difference between natural frequency and excitation frequency and converts this value into a length difference through another lookup table. The microcontroller then gives instructions to drive a stepper motor through a sequence of steps to achieve the target length and keeps the device in resonance state to harvest maximum power during operation. Different time detection intervals were studied to investigate their effect on the tuning process. This study showed that the longer time intervals increase the detection accuracy for the calculation of low excitation frequency. The amount of energy consumed during the tuning process to adjust the pendulum length is presented. In this context, the consumed energy is only needed until the resonance of the device matches the excitation frequency. The harvester system was studied numerically and experimentally. Based on the findings of this work, the natural frequency of the harvester is successfully tuned below 0.7 Hz, when the length of pendulum rod is changed from 550 mm to 900 mm, generating power from 1.78 W to 4.1 W at an optimal load resistance value of 10 Ω and 3 Ω respectively at maximum excitation amplitude of 120 mm. Therefore, the proposed pendulum system can be used as an efficient harvester for producing power in low-frequency applications (< 1 Hz)

Structural and Electrochemical Analysis of CIGS: Cr Crystalline Nanopowders and Thin Films Deposited onto ITO Substrates

A new approach for the synthesis of nanopowders and thin films of CuInGaSe2 (CIGS) chalcopyrite material doped with different amounts of Cr is presented. The chalcopyrite material CuInxGa1 − xSe2 was doped using Cr to form a new doped chalcopyrite with the structure CuInxCryGa1 − x − ySe2, where x = 0.4 and y = 0.0, 0.1, 0.2, or 0.3. The electrical properties of CuInx CryGa1 − x − ySe2 are highly dependent on the Cr content and results show these materials as promising dopants for the fabrication thin film solar cells. The CIGS nano-precursor powder was initially synthesized via an autoclave method, and then converted into thin films over transparent substrates. Both crystalline precursor powders and thin films deposited onto ITO substrates following a spin-coating process were subsequently characterized using XRD, SEM, HR-TEM, UV-visible and electrochemical impedance spectroscopy (EIS). EIS measurement was performed to evaluate the dc-conductivity of these novel materials as conductive films to be applied in solar cells

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

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Mortality of emergency abdominal surgery in high-, middle- and low-income countries

Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI). Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression. Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1⋅6 per cent at 24 h (high 1⋅1 per cent, middle 1⋅9 per cent, low 3⋅4 per cent; P < 0⋅001), increasing to 5⋅4 per cent by 30 days (high 4⋅5 per cent, middle 6⋅0 per cent, low 8⋅6 per cent; P < 0⋅001). Of the 578 patients who died, 404 (69⋅9 per cent) did so between 24 h and 30 days following surgery (high 74⋅2 per cent, middle 68⋅8 per cent, low 60⋅5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2⋅78, 95 per cent c.i. 1⋅84 to 4⋅20) and low-income (OR 2⋅97, 1⋅84 to 4⋅81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days. Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)