Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
1.
Environ Res ; 245: 117976, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38141922

ABSTRACT

To better understand the ecological effects of mariculture, the diversity distribution, determinant and interaction of microeukaryote communities from fish cage and suspended shellfish farming were investigated in three bays of South China Coast. Our alpha and beta diversity analyses showed that the difference of the microeukaryote community between fish and shellfish farming was more significant at local than regional scale, and microeukaryotes respond more to spatial effect than mariculture effect at regional scale. Mantel test, variation partitioning analysis and co-occurrence network analysis revealed that the environmental factors especially chemical and biotic factors contributed more to community assembly in fish than shellfish farming. Based on the comparisons of community composition and determinant between fish and shellfish farming, the effect mechanisms of the two farming types on microeukaryote community were proposed. Fish farming brings significant environmental variation and thus has strong bottom-up impacts on microeukaryotes, while shellfish farming exerts a grazing pressure on microeukaryotes by filter-feeding and has top-down control to them. Furthermore, the network stability analyses revealed weaker community stability in fish than shellfish farming, suggesting that the microeukaryote community was more sensitive to environmental change deduced by fish than shellfish farming. Overall, this study revealed the different influencing mechanisms of fish and shellfish mariculture on microeukaryotes, which will improve the understanding of the ecological effects of mariculture and provide guidance for the management of mariculture under future environmental pressures.


Subject(s)
Aquaculture , Shellfish , Animals , Fishes , Agriculture , China
2.
Micromachines (Basel) ; 15(4)2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38675272

ABSTRACT

In this paper, a novel asymmetric trench SiC MOSFET with a Poly-Si/SiC heterojunction diode (HJD-ATMOS) is designed to improve its reverse conduction characteristics and switching performance. This structure features an integrated heterojunction diode, which improves body diode characteristics without affecting device static characteristics. The heterojunction diode acts as a freewheeling diode during reverse conduction, reducing the cut-in voltage (Vcut-in) to a lower level than conventional asymmetric trench SiC MOSFET (C-ATMOS), while maintaining a similar breakdown voltage. Meanwhile, the split gate structure reduces gate-to-drain charge (Qgd). Through TCAD simulation, the HJD-ATMOS decreases Vcut-in by 53.04% compared to the C-ATMOS. Both Qgd and switching loss are reduced, with a decrease of 31.91% in Qgd and 40.29% in switching loss.

3.
Article in Zh | MEDLINE | ID: mdl-38686483

ABSTRACT

Objective:To explore the clinical value of supine median³ nystagmus in the accurate diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo(HC-BPPV). Methods:A total of 187 patients with HC-BPPV admitted to the First Affiliated Hospital of Xi'an Jiaotong University from June 2020 to March 2021 were selected. Among them 42 cases of Cupulolithiasis and 145 cases of Canalithiasis. The nystagmus parameters of patients left and right supine position and supine median³ position were recorded in detail by RART. According to the direction of supine median³ nystagmus, patients were divided into three groups: group A(nystagmus to weak side), group B(nystagmus to strong side), group C(negative nystagmus). The canalith repositioning manoeuvres(CRM) was carried out by utility of an automatic vestibular function diagnosis and therapy system(SRM-IV). The cure rate of CRM in three groups of HC-BPPV patients was compared, Multivariate logistic regression analysis was performed to analyze the influencing factors of CRM for HC-BPPV. Results:The cure rates of group A, group B and group C were 81.58%, 16.13% and 56.25%, respectively. The difference among the three groups was statistically significant. Then a pairwise comparison of group A, B and C, the difference was statistically significant(χ²A-B=40.294,P<0.001,χ²B-C=14.528, P<0.001,χ²A-C=11.606, P=0.001); the results of multivariate logistic regression analysis showed that the direction of supine median³ nystagmus and BMI were the influencing factors of CRM for HC-BPPV. Conclusion:The direction, intensity and duration of supine median³ nystagmus play an important role in determining the responsibility semicircular canal of HC-BPPV.


Subject(s)
Benign Paroxysmal Positional Vertigo , Semicircular Canals , Humans , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/therapy , Female , Male , Semicircular Canals/physiopathology , Supine Position , Nystagmus, Pathologic/diagnosis , Middle Aged , Vestibular Function Tests/methods , Adult , Logistic Models
4.
Micromachines (Basel) ; 15(2)2024 Jan 24.
Article in English | MEDLINE | ID: mdl-38398901

ABSTRACT

In this study, the electrical characteristics of depletion-mode AlGaN/GaN high-electron-mobility transistors (HEMTs) with a SiNx gate dielectric were tested under hydrogen exposure conditions. The experimental results are as follows: (1) After hydrogen treatment at room temperature, the threshold voltage VTH of the original device was positively shifted from -16.98 V to -11.53 V, and the positive bias of threshold was 5.45 V. When the VDS was swept from 0 to 1 V with VGS of 0 V, the IDS was reduced by 25% from 9.45 A to 7.08 A. (2) Another group of original devices with identical electrical performance, after the same duration of hydrogen treatment at 100 °C, exhibited a reverse shift in threshold voltage with a negative threshold shift of -0.91 V. The output characteristics were enhanced, and the saturation leakage current was increased. (3) The C-V method and the low-frequency noise method were used to investigate the effect of hydrogen effect on the device interface trap and border trap, respectively. It was found that high-temperature hydrogen conditions can passivate the interface/border traps of SiNx/AlGaN, reducing the density of interface/border traps and mitigating the trap capture effect. However, in the room-temperature hydrogen experiment, the concentration of interface/border traps increased. The research findings in this paper provide valuable references for the design and application of depletion-mode AlGaN/GaN HEMT devices.

5.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 37(10): 786-789;795, 2023 Oct.
Article in Zh | MEDLINE | ID: mdl-37828880

ABSTRACT

Objective:To investigate the influence of Barbecure combined with Epley on residual dizziness of horizontal canal benign paroxysmal positional vertigo(HC-BPPV) by SRM-vertigo diagnosis system. Methods:A total of 406 patients diagnosed with HC-BPPV from Nov 2021 to Nov 2022 were enrolled by rapid axial roll test and Dix-Hallpike in the department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Xi'an Jiaotong University. The patients were divided into two groups by hospital card numbers, in which the numbers that were odd were considered as group A, and the numbers that were even were considered as group B. The group A underwent two circles of Barbecure repositioning procedure by SRM-vertigo diagnosis system, while the group B underwent two circles Barbecure combined with Epley repositioning procedure by SRM-vertigo diagnosis system. The treatment was stopped on the next day when two groups of patients were cured, and those who were not cured will continue treatment with the same method. Results:The cure rate of group A was 83.41%, and the cure rate of group B was 80.51%, the difference between the two groups was not-statistically significant difference(P>0.05). The rate of residual dizziness of group A was 23.30%, the rate of residual dizziness of group B was 11.46%, the difference between the two groups was statistically significant(P<0.05). Conclusion:The Barbecure combined with Epley otoliths repositioning maneuver by SRM-vertigo diagnosis system can significantly reduce the rate of residual dizziness after the treatment of HC-BPPV, and improve the quality of life of patients.


Subject(s)
Benign Paroxysmal Positional Vertigo , Dizziness , Humans , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/therapy , Quality of Life , Patient Positioning/methods , Semicircular Canals
6.
Micromachines (Basel) ; 14(3)2023 Mar 20.
Article in English | MEDLINE | ID: mdl-36985094

ABSTRACT

Single-event gate-rupture (SEGR) in the trench vertical double-diffused power MOSFET (VDMOS) occurs at a critical bias voltage during heavy-ion experiments. Fault analysis demonstrates that the hot spot is located at the termination of the VDMOS, and the gate oxide in the termination region has been damaged. The SEGR-hardened termination with multiple implantation regions is proposed and simulated using the Sentaurus TCAD. The multiple implantation regions are introduced, leading to an increase in the distance between the gate oxide and the hole accumulation region, as well as a decrease in the resistivity of the hole conductive path. This approach is effective in reducing the electric field of the gate oxide to below the calculated critical field, and results in a lower electric field than the conventional termination.

7.
Micromachines (Basel) ; 14(5)2023 May 18.
Article in English | MEDLINE | ID: mdl-37241697

ABSTRACT

The single-event effect reliability issue is one of the most critical concerns in the context of space applications for SiC VDMOS. In this paper, the SEE characteristics and mechanisms of the proposed deep trench gate superjunction (DTSJ), conventional trench gate superjunction (CTSJ), conventional trench gate (CT), and conventional planar gate (CT) SiC VDMOS are comprehensively analyzed and simulated. Extensive simulations demonstrate the maximum SET current peaks of DTSJ-, CTSJ-, CT-, and CP SiC VDMOS, which are 188 mA, 218 mA, 242 mA, and 255 mA, with a bias voltage VDS of 300 V and LET = 120 MeV·cm2/mg, respectively. The total charges of DTSJ-, CTSJ-, CT-, and CP SiC VDMOS collected at the drain are 320 pC, 1100 pC, 885 pC, and 567 pC, respectively. A definition and calculation of the charge enhancement factor (CEF) are proposed. The CEF values of DTSJ-, CTSJ-, CT-, and CP SiC VDMOS are 43, 160, 117, and 55, respectively. Compared with CTSJ-, CT-, and CP SiC VDMOS, the total charge and CEF of the DTSJ SiC VDMOS are reduced by 70.9%, 62.4%, 43.6% and 73.1%, 63.2%, and 21.8%, respectively. The maximum SET lattice temperature of the DTSJ SiC VDMOS is less than 2823 K under the wide operating conditions of a drain bias voltage VDS ranging from 100 V to 1100 V and a LET value ranging from 1 MeV·cm2/mg to 120 MeV·cm2/mg, while the maximum SET lattice temperatures of the other three SiC VDMOS significantly exceed 3100 K. The SEGR LET thresholds of DTSJ-, CTSJ-, CT-, and CP SiC VDMOS are approximately 100 MeV·cm2/mg, 15 MeV·cm2/mg, 15 MeV·cm2/mg, and 60 MeV·cm2/mg, respectively, while the value of VDS = 1100 V.

8.
Food Chem ; 405(Pt A): 134817, 2023 Mar 30.
Article in English | MEDLINE | ID: mdl-36370577

ABSTRACT

In order to extract sulforaphane (SFN) from broccoli via green and efficient ways, a novel method based on salting-out assisted deep eutectic solvent (DES) has been developed. Compared to known organic solvent- (such as dichloromethane, ethyl acetate, n-hexane, etc.) based liquid-liquid extraction, this new N8881Cl-based DES method exhibited excellent extraction efficiency for SFN, including a significant improvement due to the salting-out effect of KH2PO4. Under optimal conditions, 97.77 % of SFN was extracted by N8881Cl-EG DES and more than 82.5 % of SFN was recovered by activated carbon from DES. In addition, further studies with Kamlet-Taft parameters and density functional theory showed that the H-bond accepting capacity of hydrophobic DES, the existing vdW interaction, and the electrostatic interaction between N8881Cl-EG DES all contributed to efficient extraction of SFN. This is the first time that the underlying mechanism for SFN extraction by DES was revealed.


Subject(s)
Brassica , Brassica/chemistry , Deep Eutectic Solvents , Sulfoxides , Isothiocyanates , Solvents/chemistry , Sodium Chloride
9.
China Econ Rev ; 75: 101831, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35821798

ABSTRACT

Based on a nationally representative survey on SMEs in China, we study the impact of government policy interventions on SMEs during the COVID-19 pandemic. Our findings are three-fold. First, relief policies in the form of payment deferrals and exemptions significantly improve SMEs' cash flows and further stimulate their operational recovery. This effect is more pronounced for firms with larger shares of high-skilled employees. Second, financial support policies do not appear to be effective in alleviating SMEs' cash constraints or encouraging the reopening of small businesses, potentially due to difficulties in accessing policy-oriented loans and misallocation of credit. Last, regional and local lock-down policies decrease SMEs' incidence of reopening and delay their expected reopening in the near future, likely by reducing consumer demand. Our findings shed new light on the policy debates on supporting SMEs during the COVID-19 pandemic.

10.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 36(11): 869-871;874, 2022 Nov.
Article in Zh | MEDLINE | ID: mdl-36347582

ABSTRACT

Objective:To evaluate the effect of body mass index (BMI) on efficacy of the repositioning procedure for horizontal canal benign paroxysmal positional vertigo (HC-BPPV). Methods:A total of 172 patients diagnosed with HC-BPPV in the First Affiliated Hospital of Xi'an Jiaotong University School of Medicine from Jan 2021 to Oct 2021 were enrolled. The patients were divided into low BMI group(BMI<24 kg/m² ) and high BMI group(BMI≥24 kg/m²ï¼‰. The two groups underwent manual repositioning procedure and vertigo treatment system procedure by Barbecue method according to their orders of visits. After two circles of repositioning, the influencing factors of repositioning were analyzed according to efficiency. Results:The effective rate of manual repositioning in HC-BPPV patients was 33.64%, and the effective rate of vertigo treatment system was 63.08%,the effective rate of vertigo treatment system repositioning was higher than that of manual repositioning (P<0.05). The effective rate of manual repositioning in the low BMI group (58.70%) was higher than that in the high BMI group (14.75%), P<0.05. The effective rate of vertigo treatment system repositioning was higher in the low BMI group (75.00%) than that in the high BMI group (54.05%), but there was no statistically significant difference between the two BMI groups (P>0.05). Logistic regression analysis suggested that BMI was the influencing factor of HC-BPPV repositioning efficacy (P<0.05). Conclusion:BMI can affect the efficacy of HC-BPPV manual repositioning. Vertigo treatment system for HC-BPPV reduction is better than manual reduction, and the efficacy is not affected by BMI.


Subject(s)
Benign Paroxysmal Positional Vertigo , Patient Positioning , Humans , Benign Paroxysmal Positional Vertigo/therapy , Body Mass Index , Patient Positioning/methods , Semicircular Canals
11.
Article in Zh | MEDLINE | ID: mdl-35822358

ABSTRACT

Objective:To compare the diagnostic performance of the rapid axial roll test(RART) and the traditional roll test(SRT)in determining the responsible semicircular canal for horizontal canal benign paroxysmal positional vertigo(HC-BPPV). Methods:A total of 400 patients diagnosed with HC-BPPV from January 2020 to December 2020 were collected and randomly divided into two groups. Among them, there were 202 cases in the RART group and 198 cases in the SRT group. The patients in the two groups performed corresponding positional test respectively, and the following treatment was based on the types of induced nystagmus. The patients with typical HC-BPPV nystagmus underwent two rounds of modified Barbecure procedure. The diagnostic accuracies of the two positional tests in locating the responsible semicircular canal were evaluated by the elicitation rate of typical nystagmus. Finally, the effects of the two tests were evaluated by comparing the recovery rate of nystagmus between the two groups after repositioning procedures. Results:The elicitation rate of nystagmus in HC-BPPV patients by RART was significantly higher than that by SRT(χ²=10.73,P<0.01 ). The effectiveness of repositioning procedure by RART in HC-BPPV patients was significantly higher than that of SRT(χ²=6.08,P<0.05). Conclusion:RART could significantly improve the accuracy in determining the responsible semicircular canal in HC-BPPV, and future studies are warranted.


Subject(s)
Benign Paroxysmal Positional Vertigo , Nystagmus, Pathologic , Benign Paroxysmal Positional Vertigo/diagnosis , Humans , Nystagmus, Pathologic/diagnosis , Semicircular Canals
SELECTION OF CITATIONS
SEARCH DETAIL