Functional regeneration of glossopharyngeal nerve through micromachined sieve electrode arrays

To assess the potential of micromachined silicon sieve electrodes for long term recording from single afferent sensory fibers, we implanted them between the cut ends of rat glossopharyngeal nerves which innervate taste and somatosensory receptors on the posterior tongue. After the implants had been in place for an average of 101 days nerve regeneration was measured using histological and electrophysiological methods. Axons of the glossopharyngeal nerve regenerated through holes in the sieves and supported the functional regeneration of taste, thermal and mechanoreceptors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29783/1/0000122.pd

Effect of thymoquinone on NRF2/NF-kB/MAPK pathway in methotrexate-induced rat testis injury

Objective(s): In this study, we aimed to investigate the protective effect of Thymoquinone (THQ) against testicular damage caused by Methotrexate (MTX). Materials and Methods: This study consists of 5 groups: Control, Olive oil, THQ, MTX, and MTX+THQ. At the end of the experiment, spermiogram analysis was performed on the rats. In addition, testicular tissues were taken and histopathology, immunohistochemistry, and biochemistry analysis were performed. Biochemical analyses were performed on the serums. Results: According to the results obtained, spermiogram values, Johnson’s testicular biopsy score, SOD, CAT, GPx, FSH, LH, and testosterone values were statistically significantly decreased in the MTX group compared to the control group. In the MTX+THQ group, spermiogram values, Johnson’s testicular biopsy score, SOD, CAT, GPx, FSH, LH, and testosterone values increased statistically significantly compared to the MTX group. NRF2 and HO-1 immunoreactivity were statistically significantly decreased in the MTX group compared to the control group. In the MTX+THQ group, NRF2 and HO-1 immunoreactivity were statistically significantly increased compared to the MTX group. The level of MDA, which is important in lipid damage, and the level of biochemistry results of TNF-α, IL1-β, and IL-6, which are important markers, and the results of p-NF-kB and P38 immunoreactivity were statistically significantly increased in the MTX group compared to the control group. In the MTX+THQ group, these parameters showed a significant decrease compared to the MTX group. Conclusion: According to these results, it is thought that THQ will play a protective role against infertility caused by chemotherapy-induced testicular damage

Investigation of the effect of thymoquinone on kidney damage in isoproterenol-induced myocardial infarction in rats and cardiorenal interactions

This study aimed to determine whether thymoquinone has any protective effects on renal tissue after an isoproterenol-induced myocardial infarction (MI). Experimental groups were formed as 4 groups (n=8). Control group (C). Thymoquinone group (THQ), 20 mg/kg single dose intragastric (i.g.) daily for seven days. Isoproterenol group (ISO) was administered 100 mg/kg intraperitoneally in two doses on days 7 and 8 of the experiment. Thymoquinone+Isoproterenol group (THQ+ISO), THQ 20 mg/kg i.g. was administered once a day for seven days. In addition, two doses of ISO 100 mg/kg i.p. were administered on the seventh and eighth days. Kidney tissues were evaluated histopathologically. Kidney tissues were evaluated histopathologically. Tumour necrosis factor alpha(TNF-α) and alpha Smooth Muscle Actin(α-SMA) immunoreactivity density changes were determined by immunohistochemistry. Glutathione(GST), Glutathione S-transferases(GSTs) and Interleukin-6(IL-6) levels were evaluated by ELISA method. Isoproterenol injection caused severe histopathological changes on kidney tissue. Also TNF-α and α-SMA levels were found to be higher in groups where ISO was administered. THQ could be effective on kidney tissue to partially correct these histopathological damages, by decreasing fibrosis and inflammation. This study shows that treatment with THQ is effective in preventing kidney damage caused by ISO-induced MI. We think that THQ as a supplementary food will be effective to prevent kidney damage

Timokinon metotreksatın neden olduğu kalp hasarını azaltır: sıçanlarda histopatolojik bir çalışma

Purpose: The study aimed to evaluate the effect of thymoquinone on cardiac tissue in MTX-induced cardiac toxicity in rats with various parameters. Materials and Methods: Group I (n=8) was administered intraperitoneal saline for 10 days. Intraperitoneal olive oil was applied to Group II (n=8) for 10 days. Group III (n=8) received 10 mg/kg Thymoquinone (THQ) intraperitoneally for 10 days. Group IV (n=8) was administered a single dose of 20 mg/kg Methotrexate (MTX), 500 mg/20 ml, intraperitoneally on the 1st day of the experiment. Group V (n=8) MTX: 20 mg/kg single dose intraperitoneally on the 1st day; THQ: 10mg/kg i.p. administered for 10 days. Since Methotrexate was in liquid form, no solvent was used. At the end of the experimental period, the rats were sacrificed for analysis of heart tissue. The structure of heart tissue was evaluated by hematoxylin eosin staining. Immunohistochemically, Connexin-43, HSP90, and HIF 1α antibodies were stained. Results: Group IV was found to have histopathological deterioration, which was ameliorated by THQ. In addition to this; Connexin-43 immunoreactivity was the lowest in Group IV compared to other groups: 108.5±7.4. Compared to other groups, HSP90 immunoreactivity was highest in Group IV: 103.6±10.4. Compared to other groups, HIF-1α immunoreactivity was highest in Group IV: 95.2 ±9.1. Conclusion: Thymoquinone has a positive effect on Connexin-43, one of the proteins providing conduction in intercalary discs, HSP90, one of the chaperones in the cell and HIF-1α expression against MTX toxicity. At the same time, THQ provides a significant improvement in cardiac tissue histopathologically by showing a cardioprotective effect

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A Feature-based Approach on Automatic Stopword Detection

In information retrieval, words that contribute little to the semantic information within a text are called stopwords. Identification of stopwords is considered an asset for many retrieval tasks as removal of such words from the text collection increase the regularization within the dataset and reduce the volume and computational complexity. Traditional techniques for identification of stopwords either involve manual construction of stopword lists by analyzing terms individually or employing sorting-based techniques that uses global term characteristics as a proxy. Due to the context-dependant and non-precise definition of what really classifies as a stopword, transfer and application of these traditional methodologies to different languages or domains leaves room for generalized and interpretable results. To address this concern, we propose a feature based supervised machine learning technique for automatic detection of stopwords. We have tested the validity of the proposed technique with extensive experiments and compared the results with a general English stopword list. Furthermore, we have evaluated the proposed technique with both formal written and social media text. The results reveal that the proposed technique leads to promising results and is also capable of addressing the changes in the dialect.</p

A Feature-based Approach on Automatic Stopword Detection

In information retrieval, words that contribute little to the semantic information within a text are called stopwords. Identification of stopwords is considered an asset for many retrieval tasks as removal of such words from the text collection increase the regularization within the dataset and reduce the volume and computational complexity. Traditional techniques for identification of stopwords either involve manual construction of stopword lists by analyzing terms individually or employing sorting-based techniques that uses global term characteristics as a proxy. Due to the context-dependant and non-precise definition of what really classifies as a stopword, transfer and application of these traditional methodologies to different languages or domains leaves room for generalized and interpretable results. To address this concern, we propose a feature based supervised machine learning technique for automatic detection of stopwords. We have tested the validity of the proposed technique with extensive experiments and compared the results with a general English stopword list. Furthermore, we have evaluated the proposed technique with both formal written and social media text. The results reveal that the proposed technique leads to promising results and is also capable of addressing the changes in the dialect.</p

An integrated telemetric multichannel sieve electrode for nerve regeneration applications.

Chronic recording from individual axons and fibers in the peripheral nervous system (PNS) is a long pursued goal to further our understanding of the nervous system and for potential control of prosthetic devices and stimulation of paralyzed muscles. This thesis demonstrates the development of a new, totally implantable system to record neural signals from axons and fibers in the PNS using the nerve regeneration of the PNS. The system is composed of a nerve regeneration electrode (sieve electrode), a radio-frequency (RF) telemetry link, and on-chip signal processing and RF interface circuitry. The electrode structure contains a large number of small holes through which axons of a severed nerve will regenerate and reinnervate its target organs. The small holes are surrounded by 100-200 \mu{\rm m}\sp2 anodized iridium oxide sites, which can be used for both recording and stimulation and have impedances of less than 100$\Omega$ 1kHz and charge delivery capacities in the 4-6 mC/cm\sp2 range. The sieve electrode is fabricated using silicon micromachining. The fabrication process is single-sided, has high yield, requires only five masks, and is compatible with integrated silicon ribbon cables. These electrodes have been implanted between the cut ends of peripheral taste fibers of rats (glossopharyngeal nerve), and axons have functionally regenerated through holes, responding to chemical, mechanical, and thermal stimuli. In addition, spontaneous action potentials were recorded using passive electrodes with a percutaneous connector. An inductively-coupled RF telemetry link has been developed using two small circular coils to transmit power and bi-directional data to a small chronic system, eliminating the need for cables and wires. The link is driven by a high efficiency class E amplifier, which is amplitude-modulated for transmitting control data to implanted on-chip circuitry. The on-chip circuitry for a small implantable neural recording unit has been developed to interface with the RF telemetry link and for signal processing. The on-chip circuitry generates a 5 V supply, the clock signal, and control data from the RF signal, and allows simultaneous recording from any user-selectable 2-of-32 channels. These signals are amplified, multiplexed, and digitized with an on-chip low-power (2mW) current-mode analog-to-digital converter before transmission to outside world using passive telemetry. The full functionality of the on-chip CMOS circuitry has been verified by fabricating it at the University of Michigan. The on-chip circuitry contains more than 5000 transistors, dissipates about 90 mW of power, and results in an implantable unit which measures 5mm x 8mm x 2mm. This is the first chip of its kind that combines signal amplification and filtering, low-power analog-to-digital conversion, and bi-directional RF telemetry for power and data transfer all integrated monolithically on a single chip.Ph.D.Applied SciencesElectrical engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/129418/2/9513286.pd