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1.
J Anaesthesiol Clin Pharmacol ; 40(2): 276-282, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38919433

RESUMEN

Background and Aims: Simulation is increasingly used in medical teaching. Various studies have evaluated different simulation models for training of regional anesthesia (RA). We compared the use of human cadaver and blue phantom models for training of regional anesthesia to novice postgraduate students of anesthesiology. Material and Methods: Fifty students were taught knobology of the ultrasonography (USG) machine. They were divided into two equal groups by computer-generated random number table, and the groups assigned were kept in sealed envelopes. In group BP, students were trained on a blue phantom model, and in group HC, students were trained on human cadaver. After training, a didactic video of sonoanatomy of the supraclavicular block was shown to all participants. The block performance was then judged on patients requiring supraclavicular block. The primary objective of the study was to compare the block performance time, and secondary objectives were the quality of image acquired, orientation of transducer to the target, identification of ultrasound artifacts, errors committed, complications, and success rate. Results: The mean block performance time was shorter in group HC compared to group BP (451.96 ± 50.25 and 526.48 ± 43.486 s, respectively; P < 0.001). The image quality score, transducer orientation to the target, and identification of USG artifacts were better in group HC compared to group BP, with lesser number of needle passes. Conclusion: Cadaver-based training produced better results compared to blue phantom simulator model for teaching of ultrasound-guided RA to novice postgraduate trainees of anesthesiology.

2.
PLoS One ; 19(5): e0304235, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38758810

RESUMEN

[This corrects the article DOI: 10.1371/journal.pone.0269504.].

3.
Indian J Anaesth ; 68(4): 366-373, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38586260

RESUMEN

Background and Aims: We compared classical (medial) and modified (lateral) thoracolumbar interfascial plane block (TLIP) with only general anaesthesia (GA) using multimodal analgesia in patients undergoing lumbar disc surgeries. Methods: In this study, 100 patients aged 18-70 years were randomised to Group cTLIP (conventional TLIP block with 20 mL of 0.25% ropivacaine with GA), Group mTLIP (modified TLIP block with 20 mL of 0.25% ropivacaine with GA), and Group C (only GA using multimodal analgesia). The primary outcome was to assess the total peri-operative opioid consumption in the first 24 h. The secondary outcomes were to assess pain score upon arriving in the post-anaesthesia care unit, time to first analgesic need after surgery, post-operative opioid consumption in 24 h, and incidence of nausea and vomiting. Results: The total peri-operative opioid consumption in Group cTLIP (507.58 (258.55) µg) and Group mTLIP (491.67 (165.39) µg) was significantly lower than that in Group C (1225.4 (237.03) µg); (P < 0.001). However, it was comparable between groups cTLIP and mTLIP (P = 0.767). Pain score was comparable in groups cTLIP and mTLIP. It was significantly lower than Group C (P = 0.001). Rescue analgesia was needed in all (100%) patients of Group C but in only 15.2% of patients of the cTLIP and mTLIP groups. No patient in groups cTLIP and mTLIP complained of nausea and vomiting in the first 24 h, whereas it was significantly higher (61.8%) in Group C (P = 0.001). Conclusion: The analgesic effect of the modified TLIP block was not superior to the conventional TLIP block. Both techniques provided the same intra-operative and post-operative analgesia for lumbar disc surgeries.

5.
ACS Appl Mater Interfaces ; 16(5): 6088-6097, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38278516

RESUMEN

Recent advancements in power electronics have been driven by Ga2O3-based ultrawide bandgap (UWBG) semiconductor devices, enabling efficient high-current switching. However, integrating Ga2O3 power devices with essential silicon CMOS logic circuits for advanced control poses fabrication challenges. Researchers have introduced Ga2O3-based NMOS and pseudo-CMOS circuits for integration, but these circuits may either consume more power or increase the design complexity. Hence, this article proposes Ga2O3-based CMOS realized using heterogeneous 3D-stacked bilayer ambipolar transistors. These ambipolar transistors consist of HfO2/NiO/Ga2O3/NiO/HfO2 heterostructures that are wrapped around by the Ti/Au gate electrode, resulting in record high electron and hole current on/off ratios of 109 and 107. The threshold voltage, subthreshold swing, and current density measured from 100 ambipolar devices (across 5 batches) are around -7.99 ± 0.92 V (p-channel) and 7.81 ± 0.81 V (n-channel), 0.59 ± 0.07 V/dec (p-channel) and 0.61 ± 0.06 V/dec (n-channel), and 0.99 ± 0.26 mA/mm (p-channel) and 58.23 ± 12.99 mA/mm (n-channel), respectively. All the 100 ambipolar devices showed decent long-term stability over a period of 200 days, exhibiting reliable electrical performance. The threshold voltage shift (ΔVTH) after negative bias stressing for a period of 3500 s is around 11.52 V (p-channel) and 10.21 V (n-channel), respectively. Notably, the n-channels exhibit ∼2 orders higher on/off ratio than the best Ga2O3 unipolar transistors at 300 °C. Moreover, the polarities of ambipolar transistors are reconfigurable into p- or n-MOS, which are integrated to demonstrate CMOS inverter, NOR, and NAND logic gates. The switching periods from "0" to "1" and from "1" to "0" of NOR are 0.12 and 0.17 µs, and those of NAND are 0.16 and 0.13 µs. This work lays the foundation of oxide-semiconductor-based CMOS for future integrated electronics.

6.
J Pediatr Endocrinol Metab ; 37(2): 170-173, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38167416

RESUMEN

OBJECTIVES: Abdominal pain is a common presentation in patients of diabetic ketoacidosis (DKA). However, this pain generally resolves with resolution of dehydration and acidosis. Persistence of abdominal pain even after resolution of ketosis and acidosis should warrant careful reassessment to find evidence of sepsis and concomitant abdominal pathology. CASE PRESENTATION: We report a rare case of type 1 diabetes mellitus in a 15 year old girl diagnosed 6 months ago who presented with mild DKA (pH 7.24, HCO3 - 13.5 mmol/L). Her hospital course was extremely stormy and despite best of our efforts she succumbed due to colonic ischemia and perforation peritonitis. CONCLUSIONS: A high index of suspicion for gut ischemia or perforation should be kept if DKA is associated with septic shock and there is suboptimal response to standard treatment. Mesenteric ischemia can occur in pediatric patients even with mild DKA having very poor diabetes control.


Asunto(s)
Diabetes Mellitus Tipo 1 , Cetoacidosis Diabética , Femenino , Humanos , Niño , Adolescente , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/diagnóstico , Cetoacidosis Diabética/terapia , Isquemia/complicaciones , Necrosis/complicaciones , Dolor Abdominal/complicaciones
7.
Cancer Biother Radiopharm ; 39(1): 19-34, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37797218

RESUMEN

It is now well understood that many signaling pathways are vital in carrying out and controlling essential pro-survival and pro-growth cellular functions. The NOTCH signaling pathway, a highly conserved evolutionary signaling pathway, has been thoroughly studied since the discovery of NOTCH phenotypes about 100 years ago in Drosophila melanogaster. Abnormal NOTCH signaling has been linked to the pathophysiology of several diseases, notably cancer. In tumorigenesis, NOTCH plays the role of a "double-edged sword," that is, it may act as an oncogene or as a tumor suppressor gene depending on the nature of the context. However, its involvement in several cancers and inhibition of the same provides targeted therapy for the management of cancer. The use of gamma (γ)-secretase inhibitors and monoclonal antibodies for cancer treatment involved NOTCH receptors inhibition, leading to the possibility of a targeted approach for cancer treatment. Likewise, several natural compounds, including curcumin, resveratrol, diallyl sulfide, and genistein, also play a dynamic role in the management of cancer by inhibition of NOTCH receptors. This review outlines the functions and structure of NOTCH receptors and their associated ligands with the mechanism of the signaling pathway. In addition, it also emphasizes the role of NOTCH-targeted nanomedicine in various cancer treatment strategies.


Asunto(s)
Drosophila melanogaster , Neoplasias , Animales , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Transducción de Señal , Receptores Notch/genética , Receptores Notch/metabolismo , Oncogenes
8.
Sci Total Environ ; 912: 169421, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38128664

RESUMEN

Calcareous soils, comprising vast areas in northern and eastern parts of India, are characterized by low soil organic carbon (SOC) with high free CaCO3 that results in low nutrient bioavailability with poor soil structure. Improvement of this soil can be achieved with conservation tillage with residue retention coupled with diversification of cropping system including legumes, and oilseeds in the system. Concerning all these, a long-term experiment was carried out in the calcareous soils having low organic carbon and high free CaCO3 (∼33 %) with varied tillage practices, viz. permanent bed with residue (PB), zero tillage with residue (ZT), and conventional tillage without residue (CT); and cropping systems viz. maize-wheat-greengram (MWGg), rice-maize (RM), and maize-mustard-greengram (MMuGg) during 2015-2021. From this study, it was observed that PB and ZT resulted in ∼25-30 % increment in SOC compared to the initial SOC, while CT showed a 4 % decrease in the SOC. Conservation tillage practices also resulted in better soil aggregation and favourable bulk density of the soil. Furthermore, PB and ZT practice exhibited 10-13 %; 15-18 %; 11-15 %; 40-60 %, 20-36 %, and 23-45 % increments in the soil available N, P, K, soil microbial biomass carbon, dehydrogenase activity, and urease activity, respectively over those under CT. Crop diversification with the inclusion of legume and oilseed crops (MMuGg, and MWGg) over cereal-dominated RM systems resulted in better soil health. Maize equivalent yield and energy use efficiency (%) were also found to be the maximum under PB, and ZT, in combination with the MMuGg system. ZT and PB also reduced the carbon footprint by 465 and 822 %, respectively over CT by elevating SOC sequestration. Hence, conservation tillage practices with residue retention coupled with diversification in maize-based cropping systems with mustard and greengram can improve soil health, system productivity, and energetics, and reduce the carbon footprint in calcareous soils.

9.
J Anaesthesiol Clin Pharmacol ; 39(3): 474-481, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38025555

RESUMEN

Background and Aim: Pneumoperitoneum (PP) and the Trendelenburg position (TP) in laparoscopic surgeries are associated with rise in intracranial pressure (ICP). The optic nerve sheath diameter (ONSD) is a surrogate marker of ICP. The study aimed to evaluate the effect of sevoflurane, propofol and propofol with dexmedetomidine as maintenance agent on ICP in TP during laparoscopic surgeries. Material and Methods: A total of 120 American Society of Anesthesiologists (ASA) physical status I/II patients, aged 18-65 years were randomly allocated into three groups: sevoflurane as group S, propofol as group P, and propofol with dexmedetomidine as group PD. The intra-abdominal pressure (IAP) was kept in the range of 12-14 mmHg and TP varied between 15°- 45° angle. The primary objective was comparison of ICP and secondary objectives were IOP, intraoperative hemodynamic and postoperative recovery characteristics among groups. The ONSD and IOP were measured in both eyes 10 min after endotracheal intubation (T0), 5 min after CO2 insufflation (T1), 5 min after TP (T2) and 5 min after deflation of gas (T3). The data were analyzed by using the Statistical Package for Social Sciences version 23. Results: ONSD and IOP at T1 and T2 were significantly higher than T0 in all groups, but no significant difference was found among the intergroup groups. Significantly lower heart rate and mean blood pressure were observed in PD group at T1 and T2 compared to group S and group P. Conclusion: The rise in ICP was comparable among sevoflurane, propofol, and propofol-dexmedetomidine combination as a maintenance agent during laparoscopic surgeries in TP.

10.
Med J Armed Forces India ; 79(4): 409-413, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37441299

RESUMEN

Background: Renal biopsy has a definite role in the management of pediatric kidney diseases. Most centers have given up the earlier practice of performing blind biopsy using Tru-Cut needle and started doing real time ultrasound-guided renal biopsy with an automated spring-loaded gun, which has become standard of care in the last decade or so. Methods: We performed a cross-sectional analysis of the pediatric biopsies conducted at our center over the years by both methods to evaluate whether ultrasound-guided renal biopsy with a disposable automated spring-loaded gun was superior to blind biopsy with a disposable needle of the same size in terms of reduction of complications and improving the yield. We also reviewed the indications and the histopathological diagnosis of pediatric renal biopsies at our center. Results: A total of 45 native kidney biopsies were performed blind and 48 ultrasound-guided biopsies using the curvilinear probe (frequency 3-5 Hz) of GE Logiq P3 ultrasound machine with disposable spring-loaded automated guns. There was a significant increase in the yield of biopsy in terms of the number of glomeruli per pass. A significant increase in the mean number of glomeruli was noted when a biopsy was performed under ultrasound guidance (P < 0.0001). Gross hematuria was significantly reduced as compared to the earlier biopsies done blind i.e., without ultrasound (P » 0.03). Nephrotic syndrome was the commonest indication for biopsy in our patients during both time periods studied. The most common histopathological diagnosis was MesPGN among the children who underwent kidney biopsy from 2005 to 2007, while Minimal Change Disease (MCD) and Focal Segmental Glomerulosclerosis (FSGS) were most frequently reported. Conclusion: Ultrasound guided kidney biopsies in pediatric age group have significant reduction in incidence of post gross hematuria and significant increase in the mean number of glomeruli per pass.

11.
Indian J Anaesth ; 67(4): 357-363, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37303875

RESUMEN

Background and Aims: Modified radical mastectomy (MRM) is associated with significant postoperative pain for which many blocks including thoracic paravertebral (TPV) block are being used. Erector spinae plane (ESP) block is a recently described technique. We planned to compare the efficacy and safety of ultrasound-guided continuous ESP and TPV blocks for postoperative analgaesia following MRM. Methods: Sixty-six patients belonging to American Society of Anaesthesiologists physical status I and II, aged 25-85 years, undergoing MRM were enrolled and randomly allocated into two groups. Ipsilateral block was given preoperatively at T3 or T4 level with 20 ml of 0.5% ropivacaine and 50 µg fentanyl. Infusion of 0.5% and 0.2% ropivacaine with fentanyl 2 µg/ml at a rate of 5 ml/hr was continued during intraoperative and postoperative period, respectively. Pain was assessed using visual analogue scale (VAS) till 24 hours. Block performance time, time to first rescue analgaesia, total amount of rescue analgaesic consumed, the incidence of procedure-related and postoperative complications, failure rate and patient satisfaction score were also recorded. Data collected were analysed using the Chi-square test or Student's t-test with the help of SPSS 22.0. Results: Demographics, baseline vitals, VAS scores both at rest and on movement, block performance time, time to first rescue analgaesia, the total amount of rescue analgaesia and patient satisfaction score were comparable in both groups (P value > 0.05). No complications were observed in either group. Conclusion: In patients undergoing MRM, continuous catheter technique ESP block is as efficacious and safe as TPV block for providing prolonged postoperative analgaesia.

12.
Trop Anim Health Prod ; 55(3): 198, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37184669

RESUMEN

Exploring genetic variability by microsatellite markers is essential for genetic improvement, preservation of indigenous germplasm and production of high-quality offspring. Lack of information on microsatellite profiling of Indian indigenous ducks (Tripura state) has stoked curiosity in this work. Genomic DNA samples from randomly selected 36 native ducks were analysed at 25 duck-specific microsatellite loci. Alleles were separated through 3.4% MetaPhore™ agarose gel electrophoresis. Allele sizes were determined using Image Lab 6 software of GelDoc™ EZ System. Allelic data were analysed by POPGENE version 1.31. Total 112 alleles were resolved and all the loci were found polymorphic with 2 to 15 alleles across the loci. Average number of allele (Na) was 4.480 ± 0.659. Allele sizes and frequencies ranged from 96 to 357 bp and 0.014 to 0.819, respectively. Average heterozygosity of Nei, effective number (Ne) of alleles and Shannon's information index (I) were 0.617 ± 0.036, 3.538 ± 0.527 and 1.184 ± 0.112, respectively. The estimates of Ne were less than the Na at all the loci, indicating prevalence of heterozygosity. Polymorphic information content (PIC) ranged from 0.252 (CAUD020) to 0.911 (CAUD019) with an average of 0.562 ± 0.040. Sixteen loci were moderate to highly polymorphic and informative (PIC ˃ 0.5). Chi-square and G-square statistics revealed Hardy-Weinberg disequilibrium at all the loci. Moderate to high level of polymorphism of the studied microsatellites indicated that these markers might be helpful for genetic characterisation and adoption of appropriate conservation strategies to exploit optimum genetic potentiality of indigenous ducks of Tripura.


Asunto(s)
Patos , Polimorfismo Genético , Animales , Patos/genética , ADN , Heterocigoto , Repeticiones de Microsatélite , Alelos , Variación Genética
13.
J Parasit Dis ; 47(1): 68-72, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36910315

RESUMEN

The tick-borne haemoprotozoan diseases are major constraint in the health and production of cattle and causes substantial losses to the livestock industry throughout the world. Tripura is a northeastern state of India characterized by a warm humid tropical climate and high rainfall which is conducive to the multiplication of vector-ticks of haemoprotozoan diseases. A total of 320 tick-infested cattle (22 male and 298 female) of either sex was selected randomly from different district of Tripura for the detection of carrier cattle infected with tick-borne haemoparasites from July, 2017 to June, 2019. Out of 320 tick-infected cattle, 4.69% prevalence of B. bigemina infection in cattle was found while Theleria spp. was not prevalent in the collected blood sample by using polymerase chain reaction. The prevalence of B. bigemina was significantly (< 0.05) higher in cattle more than 3 years of age (6.72%) compared to the 1-3 years age group (3.97%) and < 1 year age groups (1.66%). Sex-wise B. bigemina infection was significantly (< 0.05) seen only in female (5.03%) cattle infested with ticks. The district-wise B. bigemina prevalence (%) in Tripura was as in cattle; Dhalai (0.63), Sipahijala (0.31), Khowai (0.31), Gomati (0.31), South Tripura (0.63), North Tripura (0.31), Unakoti (0.31) and West Tripura (1.87) respectively. The use of PCR assays for the detection of B. bigemina and Theileria spp. in the North Eastern state of Tripura of India showed prevalence of 4.69% and 0%, respectively in tick-infested cattle. This study is the first report about the prevalence of tick-borne haemoprotozoan diseases from cattle of Tripura and suggest that babesiosis is more common disease as compared to theileriosis and is more prevalent in adult female tick-infested cattle in Tripura.

14.
Assay Drug Dev Technol ; 21(3): 126-136, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36999897

RESUMEN

The current pharmaceutical manufacturing scenario involves different techniques for the processing of materials. For example, the extraction unit is one of the essential aspects of plant-based pharmaceuticals. Recently, various kinds of extraction techniques have been used for analytical and preparative scales; among them, a supercritical fluid extractor (SCFE) is the most widely used technique for extraction. It is used for an extensive range of crude drugs and can be possible with the help of SCFE by varying temperature/pressure. Notably, it uses carbon dioxide (CO2) for extraction instead of other solvents. Simultaneously, lyophilization is an important technique used at different processing steps along with other methods. In lyophilization, CO2 is used as a cooling agent in the shelves of lyophilized equipment. It behaves as a supercritical fluid at critical pressure (Pc) of 72.7 atm and critical temperature (Tc) of 31°C. Considering the criteria mentioned earlier, there is a possibility that liquid CO2 or supercritical carbon dioxide (SC-CO2) can be used as a cooling agent in a lyophilizer and extraction solvent in SCFE. This review presents a brief outline for the possible validation parameters of the proposed novel processor; that is, SCFE/Dryer combo instrument containing Design Qualification, Installation Qualification, Operational Qualification, and Performance Qualification.


Asunto(s)
Dióxido de Carbono , Cromatografía con Fluido Supercrítico , Cromatografía con Fluido Supercrítico/métodos , Solventes , Temperatura
15.
ACS Appl Mater Interfaces ; 14(42): 47922-47930, 2022 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-36241169

RESUMEN

Transferable Ga2O3 thin film membrane is desirable for vertical and flexible solar-blind photonics and high-power electronics applications. However, Ga2O3 epitaxially grown on rigid substrates such as sapphire, Si, and SiC hinders its exfoliation due to the strong covalent bond between Ga2O3 and substrates, determining its lateral device configuration and also hardly reaching the ever-increasing demand for wearable and foldable applications. Mica substrate, which has an atomic-level flat surface and high-temperature tolerance, could be a good candidate for the van der Waals (vdW) epitaxy of crystalline Ga2O3 membrane. Beyond that, benefiting from the weak vdW bond between Ga2O3 and mica substrate, in this work, the Ga2O3 membrane is exfoliated and transferred to arbitrary flexible and adhesive tape, allowing for the vertical and flexible electronic configuration. This straightforward exfoliation method is verified to be consistent and reproducible by the transfer and characterization of thick (∼380 nm)/thin (∼95 nm) κ-phase Ga2O3 and conductive n-type ß-Ga2O3. Vertical photodetectors are fabricated based on the exfoliated Ga2O3 membrane, denoting the peak response at ∼250 nm. Through the integration of Ti/Au Ohmic contact and Ni/Ag Schottky contact electrode, the vertical photodetector exhibits self-powered photodetection behavior with a responsivity of 17 mA/W under zero bias. The vdW-bond-assisted exfoliation of the Ga2O3 membrane demonstrated here could provide enormous opportunities in the pursuit of vertical and flexible Ga2O3 electronics.

16.
PLoS One ; 17(6): e0269504, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35731723

RESUMEN

A wealth of research indicates that emotions play an instrumental role in creative problem-solving. However, most of these studies have relied primarily on diary studies and self-report scales when measuring emotions during the creative processes. There has been a need to capture in-the-moment emotional experiences of individuals during the creative process using an automated emotion recognition tool. The experiment in this study examined the process-related difference between the creative problem solving (CPS) and simple problem solving (SPS) processes using protocol analysis and Markov's chains. Further, this experiment introduced a novel method for measuring in-the-moment emotional experiences of individuals during the CPS and SPS processes using facial expressions and machine learning algorithms. The experiment described in this study employed 64 participants to solve different tasks while wearing camera-mounted headgear. Using retrospective analysis, the participants verbally reported their thoughts using video-stimulated recall. Our results indicate differences in the cognitive efforts spent at different stages during the CPS and SPS processes. We also found that most of the creative stages were associated with ambivalent emotions whereas the stage of block was associated with negative emotions.


Asunto(s)
Emociones , Expresión Facial , Humanos , Recuerdo Mental , Solución de Problemas , Estudios Retrospectivos
17.
Braz J Anesthesiol ; 2022 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-35314272

RESUMEN

Although epidural catheter insertion under ultrasound (US) guidance in the pediatric age group has been reported in the literature, it is yet to be adopted widely in clinical practice. The incomplete fusion of bones in pediatric patients provides an acoustic window for the US. The epidural space in children is at shallow depth, hence a high-frequency probe, which provides better resolution can be used. We present a case series in which real-time US-guided epidural catheter placement was performed in 10 infants in lower thoracic and upper lumbar interspaces. We reiterate that the use of real-time US during epidural catheter placement in patients increases the success rate of epidural catheter placement while decreasing procedural complications.

18.
ACS Omega ; 7(1): 804-809, 2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35036747

RESUMEN

Metal-semiconductor-metal (MSM) detectors based on Ti/Au and Ni/Au interdigitated structures were fabricated using 2.5 micrometer thick hexagonal boron nitride (h-BN) layer with both natural and 10B-enriched boron. Current-voltage (I-V) and current-time (I-t) curves of the fabricated detectors were recorded with (I N) and without (I d) neutron irradiation, allowing the determination of their sensitivity (S = (I N - I d)/I d = ΔI/I d). Natural and 10B-enriched h-BN detectors exhibited high neutron sensitivities of 233 and 367% at 0 V bias under a flux of 3 × 104 n/cm2/s, respectively. An imbalance in the distribution of filled traps between the two electric contacts could explain the self-biased operation of the MSM detectors. Neutron sensitivity is further enhanced with electrical biasing, reaching 316 and 1192% at 200 V and a flux of 3 × 104 n/cm2/s for natural and 10B-enriched h-BN detectors, respectively, with dark current as low as 2.5 pA at 200 V. The increased performance under bias has been attributed to a gain mechanism based on neutron-induced charge carrier trapping at the semiconductor/metal interface. The response of the MSM detectors under thermal neutron flux and bias voltages was linear. These results clearly indicate that the thin-film monocrystal BN MSM neutron detectors can be optimized to operate sensitively with the absence of external bias and generate stronger signal detection using 10B-enriched boron.

19.
Indian J Anaesth ; 66(12): 832-836, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36654900

RESUMEN

Background and Aims: Sedation improves patient satisfaction, comfort and acceptance of regional anaesthesia. Propofol using bispectral index (BIS)/target-controlled infusion (TCI) system can be an optimal method of sedation, as it combines objective measurement of sedation using BIS along with maintenance of a steady plasma concentration of propofol with the TCI device. The aim of this study was to ascertain the dose and safety of propofol using BIS/TCI system for sedation in patients undergoing surgeries under neuraxial anaesthesia. Methods: One hundred and seven adult patients, undergoing elective surgical procedures under spinal or combined spinal epidural anaesthesia, were recruited. Propofol infusion was started with TCI at an initial target plasma concentration (Cpt) of 1.2 µg/mL, and after equilibration between Cpt and effect site concentration (Ce), propofol was then adjusted in increments and/or decrements of 0.2 µg/mL in order to maintain a BIS value between 60 and 80. The average time to reach BIS = 80 after starting infusion was 7.32 ± 3.13 minutes. The objective was to calculate mean Cpt value maintaining BIS between 60 and 80 and to observe recovery time and complications. Results: Mean Cpt value was 1.13 ± 0.17 mg/mL with 95% confidence interval (1.10-1.16 µg/mL). In 85% of patients, a BIS value of 60-80 was maintained at Cpt ≤ 1.2 µg/mL. No patient had severe complications requiring stoppage of infusion. Conclusion: Propofol sedation using BIS/TCI system can provide safe and convenient sedation during neuraxial anaesthesia at very low plasma concentration, Cpt ≤ 1.2 µg/mL in majority of patients. There were no periprocedural complications, and recovery was rapid.

20.
Paediatr Anaesth ; 31(11): 1187-1193, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34312921

RESUMEN

BACKGROUND: Perioperative pulmonary aspiration risk increases with increased preoperative gastric volume; hence traditionally, healthy children are kept fasted overnight before surgery. Current guidelines recommend 2-h clear fluids fasting prior to anesthesia. However, emerging evidence favors allowing 3 ml/kg clear fluids up to 1-h before anesthesia. We compared the gastric volume and gastric emptying time after ingestion of 3 ml/kg and 5 ml/kg of clear fluids. METHODS: The present study enrolled 44 children, aged between 6 and 14 years. On the day of surgery, baseline gastric volume was estimated using ultrasound and patients were randomly allocated into two groups of equal number, that is, Group 3 and Group 5 (patients received 3 ml/kg and 5 ml/kg 5% Dextrose respectively). Repeated gastric ultrasound was performed at every 5 min until the gastric volume reached baseline levels. The primary objective of the study was to compare gastric emptying time. Secondary objectives included comparison of antral cross-sectional area and gastric volume. RESULTS: The demographic profile, preoperative fasting duration for clear fluids, and baseline gastric volume were comparable between groups. In both groups, compared to baseline the antral cross-sectional area and gastric volume increased significantly following fluid ingestion and then decreased exponentially to reach baseline within 1-h. The median (IQR) (range) gastric emptying time (minutes) [35.0 (28.8, 40.0) (20.0-45.0) in group 3 and 40.0 (28.8, 45.0) (20.0-50.0) in group 5] and emptying half-time (minutes) [17.0 (15.7, 21.5) (14.4-24.0) in group 3 and 18.6 (16.0, 22.0) (15.1-23.8) in group 5] were comparable [median difference -5 (95% CI -7.8 to 2.1) and -1.5 (95% CI -2.3 to 1.0), respectively] (p = .16 and p = .44, respectively). CONCLUSION: As the gastric volume returned to baseline within 1-h even after ingesting 5 ml/kg clear fluids, the preoperative fasting time can be reduced to 1-h and healthy children undergoing elective procedure can be safely allowed to drink up to 5 ml/kg clear fluids.


Asunto(s)
Vaciamiento Gástrico , Estómago , Adolescente , Niño , Ayuno , Humanos , Proyectos de Investigación , Estómago/diagnóstico por imagen , Ultrasonografía
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