Fast Recovery Time Research Articles

Laser hemorrhoidoplasty versus LigaSure™ hemorrhoidectomy versus diathermy hemorrhoidectomy in treatment of grade III and IV Hemorrhoids: A non-randomized prospective trial

BackgroundThrough the past decades, various surgical methods have been introduced as new modalities for the management of grade III and IV hemorrhoidal disease HD, to provide an effective and less invasive operation in comparison with conventional haemorrhoidectomy which is the gold standard surgical treatment. MethodsThis study was conducted at Alexandria Main University Hospital. Ninety three patients with grade III and IV HD were enrolled in our study, thirty-one patients treated with diathermy hemorrhoidectomy DH (group A), thirty-one patients with LigaSure™ hemorrhoidectomy LH (group B),and thirty-one patients with Laser hemorrhoidoplasty LHP (group C). Assessment of postoperative pain, intra and postoperative bleeding, operative time, time to return to work, quality of life using Hemorrhoidal Disease Symptom Score HDSS, and Short Health Scale for hemorrhoidal disease SHSHD and patient satisfaction were recorded and analyzed. ResultsThe postoperative pain according to Visual analogue scale VAS scores from the evening of the procedure till the fourth week postoperatively were significantly higher in group A patients compared to group B and C patients, however, no significant statistical difference was found between group B and C patients. There was significant statistical difference between each group for intra-operative bleeding, operative time, and time to return to work with advantage for LHP. LH led to significant improvement in both HDSS, SHSHD when compared with LHP (p = 0.015*and p = p3<0.001*respectively) and when compared with DH, however, only SHSHD was statistical significance (p = 0.001*). The median score for patient satisfaction was 6 in the 3 groups (range: 3–7 group A, 3–7 group B and 2–6 group C) with no statistical significance. ConclusionLH and LHP are associated with significantly less postoperative pain and give superior results than DH in terms of less operative time, intraoperative blood loss, postoperative complications, and faster recovery time, with significantlys better health-related quality of life after LH.

Flexible electrospinning pressure sensing film with wide pressure detection range and high sensitivity

The preparation of flexible sensors with high sensitivity, wide detection range and good stability is a hot and difficult topic in recent years. Therefore, it is necessary to develop a pressure sensor with high sensitivity and wide pressure range. In this paper, multiwall carbon nanotubes (MWCNT)/thermoplastic polyurethane elastomer rubber (TPU) nanofiber conductive films with microporous structure are prepared by electrospinning using MWCNT as a conductive material. Then, a flexible pressure sensor with a sandwich structure is prepared while the film is used as the central layer. The pressure detection range can reach 364 kPa during testing. And when the pressure range is 201 ∼ 364 kPa, the sensitivity is still as high as 0.0658 kPa−1, with fast response time and recovery time. The sensor has good stability in cycle testing and still maintains high sensitivity after washing, proving that it has good washing resistance. The sensor has great potential for application in sports and health monitoring.

Synthesis and Characterization of Flower-Like Cobalt-Doped ZnO Nanostructures for Ammonia Sensing Applications

Abstract The present study uses the co-precipitation method to explore the synthesis of zinc oxide and cobalt-doped ZnO sensors, encompassing a range of cobalt concentrations from 1 to 4 wt.%. The synthesized samples undergo comprehensive analysis to evaluate their structural, morphological, optical, and gas-sensing properties. X-ray diffraction revealed a hexagonal Wurtzite structure, and the crystallite size decreased from 16.92 to 15.39 nm. Energy-dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy collectively affirmed the presence of cobalt. Scanning electron microscopy was used to analyze the morphological characteristics. The Tauc-plot was used to determine the optical bandgap via diffuse reflectance spectroscopy. As cobalt doping increased, the band gap increased from 3.18 to 3.23 eV. Further, atomic force microscopy and Brunauer-Emmett-Teller analysis were used to assess the surface topography and pore size distribution. The AFM measurements indicated roughness within 435-700 nm. The BET analysis revealed mesoporous properties, with surface area ranging between 18.657 to 21.962 m2/g. Subsequently, the gas-sensing capabilities of the Co-doped ZnO sensors were examined for various volatile organic compounds at room temperature. The sensor with 4% Cobalt doping exhibited a fast response and recovery time of 21 and 20 seconds for 2 ppm of NH3

The Correlation between Body Mass Index (BMI) and Recovery Time on General Anesthesia Patient Using Endotracheal Tube (ET)

Conscious recovery time is the time it takes for the patient to be removed from the conscious recovery room when the patient is fully conscious. Patients who are unconscious within more than 15 minutes are considered prolonged, even to respond to a stimulus in highly susceptible patients requires 30-45 minutes after general anesthesia drugs are stopped. One of the causes of lengthening the time to recover consciousness is the Body Mass Index (BMI) in patients which can increase the potential of anesthetic drugs given. The purpose of this study was to determine the relationship between Body Mass Index (BMI) and conscious recovery time in general anesthesia patients using Endotracheal Tube (ET) at RSUD Dr. Soedirman Kebumen. The method of ths study was correlation analitik with a cross-sectional approach. The sample of this study amounted to 48 respondents with consecutive sampling technique. Data analysis was carried out using the Kendall Tau test. The results of the study obtained 86.5% of respondents had a fast conscious recovery time (&lt;15 minutes) and 13.5% of respondents had a prolonged conscious recovery time (&gt;15 minutes). Of the results of the kendall tau correlation test obtained results with a significancy p value of 0.000 &lt; 0.05 which means there is a relationship between the body's mass index to the recovery time of consciousness after general anesthesia with the endotracheal tube. The conclusion of this study is that majority of respondents who have a quick recovery time of less tha 15 minutes are respindents with a normal body mass index. Patient with a fat or obese BMI will receive a higher dose of anesthetic medication compared to patients in the thin category. When the anesthetic drug is given a higher concentration, the effect of the ansthetic drug will be longer.

Theoretical model of passive mode-locking in terahertz quantum cascade lasers with distributed saturable absorbers

Abstract In research and engineering, short laser pulses are fundamental for metrology and communication. The generation of pulses by passive mode-locking is especially desirable due to the compact setup dimensions, without the need for active modulation requiring dedicated external circuitry. However, well-established models do not cover regular self-pulsing in gain media that recover faster than the cavity round trip time. For quantum cascade lasers (QCLs), this marked a significant limitation in their operation, as they exhibit picosecond gain dynamics associated with intersubband transitions. We present a model that gives detailed insights into the pulse dynamics of the first passively mode-locked QCL that was recently demonstrated. The presence of an incoherent saturable absorber, exemplarily realized by multilayer graphene distributed along the cavity, drives the laser into a pulsed state by exhibiting a similarly fast recovery time as the gain medium. This previously unstudied state of laser operation reveals a remarkable response of the gain medium on unevenly distributed intracavity intensity. We show that in presence of strong spatial hole burning in the laser gain medium, the pulse stabilizes itself by suppressing counter-propagating light and getting shortened again at the cavity facets. Finally, we study the robustness of passive mode-locking with respect to the saturable absorber properties and identify strategies for generating even shorter pulses. The obtained results may also have implications for other nanostructured mode-locked laser sources, for example, based on quantum dots.

Construction of strain responsive Ti-containing carboxymethyl cellulose hydrogel with transitional coordination precursor

Due to marvelous sensitivity and flexibility, conductive hydrogels are popularly used as strain sensors in intelligent skin and wearable electronic devices fields. However, hydrogel tends to be destroyed after long-term use or in accident, leading to performance degradation. Herein, we developed an environmental-friendly Ti-containing conductive hydrogel. The hydrogel network was constructed via a simple two-step method with coordination reaction and amidation reaction based on a metal ion precursor from transitional coordination. The synergies of reversible metal coordination bonds and dynamic hydrogen bonds endowed the hydrogel with excellent self-healing properties (3 h, 93.66 %), tensile properties (136.46 kPa), compression properties (1.122 MPa), and anti-fatigue performance. At the same time, the hydrogel showed excellent self-adhesion, even underwater. Due to Ti4+, electrical conductivity of the hydrogel was visibly enhanced (σ = 25.64 mS·cm−1), which resulted in fast response (TS [time sensitivity] = 24.78 s−1) and short recovery time (153 ms). As a flexible strain sensor, the hydrogel with stable conductivity and high sensitivity could precisely detect and distinguish a series of human motions, even different letter pronunciations. These remarkable features make it a promising application in the fields of intelligent skin and wearable electronic devices.

High-Performance Flexible Broadband Photothermoelectric Photodetectors Based on Tellurium Films.

Mid- and far-infrared photodetectors that can operate at room temperature are essential for both civil and military applications. However, the widespread use of mid-to-far-infrared photonic technology faces challenges due to the need for low-temperature cooling of existing commercial semiconductors and the limited optical absorption efficiency of two-dimensional materials. We have utilized the photothermoelectric effect to fabricate a self-powered, broadband, and high-performance photodetector based on a one-dimensional tellurium nanorod array film. The device surpasses energy band gap limitations, functioning even at wavelengths up to approximately 10,600 nm. In particular, the detectivity of the device can reach 4.8 × 109 Jones at 4060 nm under room-temperature conditions, which is an order of magnitude higher than that of commercially available photodetectors. It demonstrates fast response and recovery times of 8.3 and 8.8 ms. Furthermore, the device demonstrates outstanding flexibility withstanding over 300 bending cycles and environmental stability. These results suggest a viable approach for designing and developing high-performance, room-temperature, wearable optoelectronic devices.

Twin-Delayed Deep Deterministic Policy Gradient Algorithm to Control a Boost Converter in a DC Microgrid

A stable output voltage of a boost converter is vital for the appropriate functioning of connected devices and loads in a DC microgrid. Variations in load demands and source uncertainties can damage equipment and disrupt operations. In this study, a modified twin-delayed deep deterministic policy gradient (TD3) algorithm is proposed to regulate the output voltage of a boost converter in a DC microgrid. TD3 optimizes PI controller gains, which ensure system stability by employing a non-negative, fully connected layer. To achieve optimal gains, multi-deep reinforcement learning agents are trained. The agents utilize the error signal to obtain the desired output voltage. Furthermore, a new reward function used in the TD3 algorithm is introduced. The proposed controller is tested under load variations and input voltage uncertainties. Simulation and experimental results demonstrate that TD3 outperforms PSO, GA, and the conventional PI. TD3 exhibits less steady-state error, reduced overshoots, fast response times, fast recovery times, and a small voltage deviation. These findings confirm TD3’s superiority and its potential application in DC microgrid voltage control. It can be used by engineers and researchers to design DC microgrids.

Broadband nonlinear optical response and sub-picosecond carrier dynamics in graphene-SnSe2 van der Waals heterostructures.

The van der Waals (vdWs) heterostructures, with vertical layer stacking structure of various two-dimensional (2D) materials, maintain the reliable photonic characteristics while compensating the shortcomings of the participating individual components. In this work, we combine the less-studied multilayer tin selenide (SnSe2) thin film with one of the traditional 2D materials, graphene, to fabricate the graphene-based vdWs optical switching element (Gr-SnSe2) with superior broadband nonlinear optical response. The transient absorption spectroscopy (TAS) measurement results verify that graphene acts as the recombination channel for the photogenerated carrier in the Gr-SnSe2 sample, and the fast recovery time can be reduced to hundreds of femtoseconds which is beneficial for the optical modulation process. The optical switching properties are characterized by the I-scan measurements, exhibiting a saturable energy intensity of 2.82 mJ·cm-2 (0.425 µJ·cm-2) and a modulation depth of 15.6% (22.5%) at the wavelength of 1030 nm (1980nm). Through integrating Gr-SnSe2 with a cladding waveguide, high-performance picosecond Q-switched operation in the near-infrared (NIR) and mid-infrared (MIR) spectral regions are both achieved. This work experimentally demonstrates the great potential of graphene-based vdWs heterostructures for applications in broadband ultrafast photonics.

Evaluation of the efficacy of N-acetylcysteine and bromhexine compared with standard care in preventing hospitalization of outpatients with COVID-19: a double blind randomized clinical trial

Introduction and aimSince its emergence in December 2019, the coronavirus disease caused by the severe acute respiratory syndrome coronavirus 2 has become a global emergency, spreading rapidly worldwide. In response to the early referral of these patients to outpatient health centers, we decided to seek more effective treatments in the early stages of their referral. This study aims to prevent both the progression and deterioration of the physical conditions of COVID-19 patients, reduce the rate of referrals, and mitigate the risks of hospitalization and death. Material and methodsConducted at Dibaj Therapeutic Center, Hamadan City, Iran, a double-blind randomized controlled trial encompassed 225 COVID-19 patients from April to September 2022. Ethical approval was obtained from Hamadan University of Medical Sciences (Approval No.: IR.UMSHA.REC.1400.957), with the protocol registered in the Iranian Registry of Clinical Trials (Registration No. : IRCT20220302054167N1). In this study, we included patients who tested positive for COVID-19- PCR and were symptomatic, excluding those who were pregnant or had received a COVID-19 vaccine. Patients with oxygen saturation above 92% were allocated to three groups: Group A received N-acetylcysteine, Group B received Bromhexine, and Group C received standard care. Follow-ups on oxygen levels, symptoms, and hospitalization needs were conducted on days 7 and 14, with hospitalized patients monitored for one month post-hospitalization. ResultsThe study found that both N-acetylcysteine and Bromhexine can effectively reduce hospitalization rates and mortality and shorten the duration of hospitalization. The third visit of patients who received N-acetylcysteine showed an increase of 1.33% in oxygen saturation compared to their first visit, and in patients who received Bromhexine, this increase was 1.19%. The mortality rate was 9.33% in the control group and zero in both groups of patients who received medication. ConclusionIn conclusion, the results of this study indicate that NAC and bromhexine may be effective in the treatment of patients with positive COVID-19, with a lower hospitalization rate, shorter hospitalization, faster recovery time, and reduced mortality compared to the control group.

ECRLoRa: LoRa Packet Recovery under Low SNR via Edge–Cloud Collaboration

Low-Power Wide-Area Networks (LPWANs), extensively utilized for connecting billions of IoT devices, encounter wireless interference challenges in unlicensed frequency bands. Cutting-edge research suggests employing Received Signal Strength Indication (RSSI) sequences for error detection to mitigate interference-related issues. Nevertheless, the effectiveness of this method significantly declines under low signal-to-noise ratios (SNRs). Additionally, long-range communication often results in low SNR received signals, sometimes even below the noise floor. Targeting this fundamental issue, this article proposes the LPWAN packet technique, broadly applicable across diverse scenarios through edge–cloud collaboration. On the edge side, we propose an innovative architecture that fully exploits spatial distribution and interference independence in the field. Rather than utilizing resource-intensive RSSI-based error detection, we leverage a lightweight coding scheme for error detection at the Long Range (LoRa) edge, forwarding correct frames to the cloud. On the cloud side, packet recovery is achieved utilizing group-weighted voting. We design and implement ECRLoRa with commercially available devices (SemTech’s SX1278 and SX1302 LoRa chipsets) and assess its performance in low SNR environments. Our thorough evaluation demonstrates that our approach attains a Packet Recovery Ratio of 96% with low SNR (i.e., below −10 dB), resulting in 1.8× throughput, 7.5× faster recovery time, and 4.92× average accuracy compared to state-of-the-art cloud-optimized application layer solutions.

A NiO@Ti based linear photoelectrochemical type ultraviolet photodetector

Omnidirectional detection is widely used in optical tracking systems, omni-directional cameras and optical field measurements and so on. However, the planar structures of ultraviolet (UV) photodetectors (PDs) limit their application in omnidirectional detection. In this work, the NiO nanosheets were fabricated on a titanium (Ti) wire substrate by hydrothermal method and then assembled a photoelectrochemical (PEC) type UV photodetector (PD). Under ultraviolet (UV) irradiation of 35 mW cm−2 @ 365 nm, the PD exhibits a stable photocurrent of 1.53 μA cm−2 and repeatable switching cycles. Also, the PD presents fast response and recovery times of 0.074 s and 0.130 s, respectively. Particularly, the PD based on NiO@Ti possesses excellent response for rotation angles in the range from 0° to 360° under UV light irradiation.

Effective doses of ciprofol combined with alfentanil in inhibiting responses to gastroscope insertion, a prospective, single-arm, single-center study

BackgroundCiprofol is a novel intravenous sedative and anesthetic. Studies have shown that it features a rapid onset of action, a fast recovery time, slight inhibition of respiratory and cardiovascular functions, and a low incidence of adverse reactions. This study aims to explore the median effective dose (ED50) and the 95% effective dose (ED95) of ciprofol in inhibiting responses to gastroscope insertion when combined with a low dose of alfentanil, and to evaluate its safety, to provide a reference for the rational use of ciprofol in clinical practices.MethodsWe included 25 patients aged 18–64 years of either sex who underwent gastroscopy under intravenous general anesthesia, with a Body Mass Index (BMI) 18–28 kg/m2, and an American Society of Anesthesiologists (ASA) grade I or II. In this study, the dose-finding strategy of ciprofol followed a modified Dixon’s up-and-down method with an initial dose of 0.30 mg/kg and an increment of 0.02 mg/kg. Ciprofol was administered after intravenous injection of 7 µg/kg of alfentanil, and 2 min later a gastroscope was inserted. When the insertion response of one participant was positive (including body movement, coughing, and eye opening), an escalation of 0.02 mg/kg would be given to the next participant; otherwise, a de-escalation of 0.02 mg/kg would be administered. The study was terminated when negative response and positive response alternated 8 times. A Probit model was used to calculate the ED50 and ED95 of ciprofol in inhibiting responses to gastroscope insertion when combined with alfentanil. Patients’ recovery time, discharge time, vital signs and occurrence of adverse reactions were recorded.ResultsThe ED50 of single-dose intravenous ciprofol injection with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Patients’ recovery time and discharge time were 11.04 ± 1.49 min and 9.64 ± 2.38 min, respectively. The overall incidence of adverse reactions was 12%.ConclusionThe ED50 of ciprofol combined with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Ciprofol showed a low incidence of anesthesia-related adverse events.Trial registrationhttp://www.chictr.org.cn (ChiCTR2200061727).

A comprehensive review on corneal crosslinking.

Corneal crosslinking (CXL) represents a paradigm shift in the management of corneal ectatic disorders. Before CXL was introduced, patients would need specialty contact lenses and possible corneal transplantation. CXL involves a biochemical reaction in which ultraviolet A light is used in conjunction with Riboflavin to form crosslinks in between corneal stromal collagen. This leads to strengthening and stabilizing of the collagen lamellae, resulting in mechanical stiffening of the cornea. Multiple protocols have been proposed including epithelium on versus off and varying light intensity and duration of treatment. All protocols appear to be safe and effective with few reported complications including infection, stromal haze, scarring, and endothelial toxicity. Overall, CXL has demonstrated to halt the progression of the disease clinically and in keratometry readings and improve the quality of life for patients. It is a minimally invasive, cost-effective procedure that can be performed in an outpatient setting with a fast recovery time and long-lasting results.

Pushing boundaries in cardiac surgery: minimally invasive mitral valve repair combined with tricuspid valve repair and/or other concomitant procedures.

Minimally invasive mitral valve repair/replacement has emerged as a widely accepted surgical approach for managing mitral valve disorders. Continuous technological progress has contributed to the refinement of this procedure, leading to improved safety, decreased surgical trauma, and faster recovery times. Despite these advancements, there remains a scarcity of data concerning minimally invasive complex mitral valve repair surgeries when combined with additional procedures. Between November 2008 and December 2022, 153 patients underwent an operation using a minimally invasive technique. All patients underwent mitral valve surgery for severe mitral valve insufficiency/stenosis in combination with at least one additional procedure for tricuspid valve repair (n = 52, 34%), patent foramen ovale or atrial septal defect closure (n = 34, 22.2%), left atrial appendage occlusion (n = 25, 16.3%), or electrophysiological procedure (n = 101, 66.0%). Two concomitant procedures were conducted in 98 patients (64.1%), three concomitant procedures in 49 patients (32%), and four concomitant procedures in 6 patients (3.9%). Surgical success was achieved in 99.3% of the patients (n = 152), one patient required a revision of the mitral valve repair on the first postoperative day due to systolic anterior motion phenomenon. Mitral valve repair was performed in 136 patients (88.9%), while 15 patients (9.8%) received a mitral valve replacement as per a preoperative decision due to severe mitral valve stenosis, and two patients (1.3%) underwent other mitral valve procedures. Therapeutic success in treating atrial fibrillation was achieved in 86 patients (85.1%) of the 101 who received an additional maze-procedure. The 30-day mortality rate was 0.7%, with one patient succumbing to respiratory failure. Neurological complications occurred in 7 patients (4.6%). Freedom from reoperation was calculated as 98% at 5-year follow-up and 96.5% at 10-year follow-up. Minimally invasive mitral valve surgery, even when performed alongside concomitant procedures, stands out as a reproducible and safe technique with outstanding outcomes. It is imperative to advance towards the next frontier in minimally invasive surgery, encouraging experienced surgeons to undertake more complex procedures using minimally invasive approaches. These results help envision extending the boundaries of minimally invasive surgery by performing complex mitral valve procedures and associated interventions entirely through endoscopic means in suitable patients.

Minimally invasive subtalar joint and talonavicular joint preparation for hindfoot arthrodesis: A Cadaveric study evaluating structures at risk

Minimally invasive surgery (MIS) is growing in popularity due to smaller incisions, faster recovery times with less post-operative pain, and measurable decreases in morbidity. Our center performed an MIS hindfoot joint preparation about the talonavicular and subtalar joints and defined structures at risk in order to make this procedure more reproducible. Using ten fresh frozen cadaver limbs, we created a medial and lateral portal for talonavicular joint (TN) access, and an additional portal for subtalar joint (STJ) access to prepare the subtalar joint. After denuding the aforementioned joints of cartilage, the specimens were dissected to identify nearby anatomical structures. We documented the position of the peroneal sheath and sural nerve relative to the STJ portal, and the position of the dorsalis pedis artery (DP), medial dorsal cutaneous nerve (MDCN), extensor hallucis longus (EHL), extensor digitorum longus (EDL), tibialis anterior (TA), and tibialis posterior (TP) tendons relative to the TN portals. The average distance of the sural nerve and the peroneal sheath from the STJ portal was 34.21 mm and 14.12 mm respectively. The average distance of the DP, MDCN, and deep peroneal nerve from the medial and lateral TN portals were 13.31 mm, 11.54 mm, and 17.14 respectively. No neurovascular structures were transected throughout joint preparation. To our knowledge this is the first study looking into structures at risk for this specific procedure.

High-performance humidity sensor based on Ag-doped ZnGa2O4/ZnO composite nanofibers

Ag-doped ZnGa2O4/ZnO composite nanofibers to achieve a reliable hysteresis and a fast response recovery time.

Fabrication and performance of capacitive humidity and strain sensors that incorporate 3D-printed nanocomposite electrodes

This work reports on advances in capacitive humidity and strain sensor technologies through the development of state-of-the-art 3D-printed Interdigitated Electrodes (IDEs) coated with a unique GO/ PVA coating. These IDEs are constructed using a novel composite filament of MWCNTs and polylactic acid (PLA) that offer superior flexural strength and electrical properties compared to conventional polymer matrices.We show that the GO/ PVA coating appears to be sensitive over the full range of relative humidity (RH) from 0% to 100%, with a remarkable capacitance change of 300 pF/%RH. Fast response and recovery times of 60 and 42 s, respectively, have been measured outperforming existing works that utilize metal electrodes. Regarding temperature dependence, the coatings endure conditions ranging from ambient to −25 °C, even in the presence of ice. Furthermore, at 50% RH, the sensors are shown to achieve a maximum sensitivity of 34.2 within a strain range of up to 2%.In conclusion, this work represents a significant advancement in cutting-edge sensor technologies, offering unprecedented capabilities for humidity and strain sensing performance for a wide range of applications.

Synthesis and characterization of ZrO2-ZnO heterojunction composite for isopropanol detection.

We prepared ZrO2-ZnO heterojunction composites by a simple hydrothermal method as materials sensitive to isopropanol gas. The 5% ZrO2-ZnO sample presented a uniform rod-like structure. The optimum operating temperature, sensitivity and response/recovery times were measured to investigate the response of ZrO2-ZnO composites to isopropanol. The sensor based on 5% ZrO2-ZnO composites at an optimum temperature of 260 °C had a response to 100 ppm isopropanol of up to 172.46, which was about 3.6 times higher than that of pure ZnO. The sensor also exhibited fast response and recovery times of 5 s and 11 s, respectively. The gas-sensitive properties can be attributed to the rod-like structure, heterojunction structure and catalytic activity of ZrO2. These results would contribute in expanding the application of ZrO2 in gas sensors.

Boron-doped graphene topological defects: unveiling high sensitivity to NO molecule for gas sensing applications.

Global air quality has deteriorated significantly in recent years due to large emissions from the transformation industry and combustion vehicles. This issue requires the development of portable, highly sensitive, and selective gas sensors. Nanostructured materials, including defective graphene, have emerged as promising candidates for such applications. In this work, we investigated the B-doped topological line defect in graphene as a sensing material for various gas molecules (CO, CO2, NO, and NH3) based on a combination of density functional theory and the non-equilibrium Green's function method. The electronic transport calculations reveal that the electric current can be confined to the line defect region by gate voltage control, revealing highly reactive sites. The B-doped topological line defect is metallic, favoring the adsorption of NO and NH3 over CO and CO2 molecules. We notice changes in the conductance after gas molecule adsorption, producing a sensitivity of 50% (16%) for NO (NH3). In addition, the recovery time for nitride gases was calculated for different temperatures and radiation frequencies. At 300 K the ultraviolet (UV) has a fast recovery time compared to the visible (VIS) one by about two orders of magnitude. This study gives an understanding of how engineering transport properties at the microscopic level (by topological line defect and chemical B-doping) leads to promising nanosensors for detecting nitride gas.