Accountability audit of natural resources and total factor productivity-Evidence based on Chinese listed companies.

Based on a natural event, namely a pilot accountability audit of natural resources conducted by local officials in 2014, this study empirically investigates the impact of the pilot on the total factor productivity (TFP) of enterprises. The study utilizes the Differences-in-Differences model with an observation window spanning from 2012 to 2015. The findings indicate a significant reduction in the total factor productivity of enterprises in the pilot area due to the implementation of the pilot program. The study identifies that this impact is primarily driven by increased production costs and decreased investment. Further analysis reveals heterogeneity in the effects, with regions characterized by low levels of economic development, distortions in the production element market, low competition in industries, heavy asset-intensive industries, large enterprises, and absolute holding enterprises experiencing a more pronounced impact of the audit on total factor productivity. Overall, this study sheds light on the influence of accountability audits of natural resources on the real economy and offers valuable insights for policymakers.

An enhanced sensitive electrochemical immunosensor based on efficient encapsulation of enzyme in silica matrix for the detection of human immunodeficiency virus p24.

We report a new electrochemical immunosensor for enhanced sensitive detection of human immunodeficiency virus p24 (HIV-p24) based on graphene oxide (GO) as a nanocarrier and enzyme encapsulated in carbon nanotubes-silica as a matrix in a multienzyme amplification strategy. Greatly enhanced sensitivity was achieved by using the bioconjugates featuring horseradish peroxidase-HIV-p24 signal antibody (HRP-HIV-p24) linked to functionalized GO and thionine (TH) as well as efficient encapsulation of enzyme (HRP) in the silica matrix with retained bioactivity. After a sandwich immunoreactions, the HRP in carbon nanotubes-silica matrix and the HRP-HIV-p24-TH/GO captured onto the electrode surface produced an amplified electrocatalytic response by the reduction of enzymatically oxidized thionine in the presence of hydrogen peroxide. The increase of response current was proportional to the HIV-p24 concentration in the range of 0.5 pg/mL-8.5 ng/mL with the detection limit of 0.15 pg/mL, which was lower than that of the traditional sandwich electrochemical measurement for HIV-p24. The amplified immunoassay developed in this work shows acceptable stability and reproducibility, and the assay results for HIV-p24 spiked in human plasma also show good accuracy. This simple and low-cost immunosensor shows great promise for detection of other proteins and clinical applications.

Simple approach for ultrasensitive electrochemical immunoassay of Clostridium difficile toxin B detection.

Clostridium difficile toxin B (Tcd B), as one of the primary contributing factors to the pathogenesis of C. difficile-associated diseases, has raised serious public concerns due to its virulence, spore-forming ability and persistence with major types of infectious diarrhea diseases, and been used as a potential biomarker in clinical diagnoses. Thus, a simple method for the determination of Tcd B was developed based on a sandwich-type electrochemical immunosensor. Greatly enhanced sensitivity was achieved based on fabricating the immunosensor by layer-by-layer coating carbon nanotubes (MWCNTs), Prussian blue (PB), Chitosan (CS), Glutaraldehyde (GA) composite on the working electrode as well as using graphene oxide (GO) as a nanocarrier in a multienzyme amplification strategy. In comparison with conventional methods, the proposed immunoassay exhibited high sensitivity and selectivity for the detection of Tcd B, providing a better linear response range from 0.003 to 320 ng/mL and a lower limit of detection (LOD) of 0.7 pg/mL (S/N=3) under optimal experimental conditions. The immunosensor exhibited convenience, low cost, rapidity, good specificity, acceptable stability and reproducibility. Moreover, satisfactory results were obtained for the determination of Tcd B in real human stool samples, indicating that the developed immunoassay has the potential to find application in clinical detection of Tcd B and other tumor markers as an alternative approach.

Removal of a large amount of pretarsal tissue through three mini incisions in the construction of a double eyelid.

BACKGROUND: The surgical procedure aimed at constructing the upper eyelid crease is the cosmetic operation most commonly requested by Asian patients. The incisional approach leaves a permanent crease, but the swelling period can last longer than 3 months, and a distinct scar usually is unavoidable. Many mini-incisional techniques with incisions of varying sizes and locations have been developed, but the removal of pretarsal tissue has not been sufficient because these procedures wipe out only small pockets of soft tissue immediately inferior to skin for placement of the suture. Thus, the formed double eyelid may not be durable. The technique the authors introduce is a modified mini-incisional technique that combines the benefits of both the incisional and the usual mini-incisional methods. METHODS: Three 3- to 4-mm mini-incisions were made on each upper eyelid. The orbicularis muscle was isolated carefully from the skin and then cut off as much as possible in three directions: down (toward the palpebral margin), left, and right. Finally, the three incisions were sutured, and a vivid fold was created. This technique was applied for 110 patients. The follow-up period ranged from 3 to 12 months. The patients were welcomed for further treatment if any problems occurred at any time. An extra 3 years of follow-up evaluation was applied for 24 patients (46 cases) to assess the long-term maintenance of the fold. RESULTS: This study enrolled 110 patients (212 cases). A natural-looking skin fold appeared after the edema period. The scar was not obvious. Disappearance of the fold was not found in any case during 3-12 months (mean, 9 months) of follow-up evaluation. Obvious shifting of the fold was found in four cases during the additional 3 years of follow-up evaluation, but disappearance of the fold was not found in any case. CONCLUSION: This modified technique was found to be successful in developing a natural-appearing, long-lasting suprapalpebral fold with an inconspicuous scar. It combines the best of both the open and usual mini-incisional techniques. Because a large amount of pretarsal soft tissue is removed, the double fold is less likely to fade away. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article.

Synthesis, characterization, and photocatalytic activities of titanate nanotubes surface-decorated by zinc oxide nanoparticles.

Nanoscaled zinc oxide (ZnO) particles with different amounts are coated on titanate nanotubes (TNTs) by a facile chemical method at room temperature. The characterizations of XPS, TEM, XRD and UV-vis spectra confirm that pure hexagonal wurtzite ZnO nanoparticles with an average size of about 9nm are distributed on the surfaces of TNTs evenly and attached strongly. The photocatalytic activities of the ZnO-TNTs nanocomposite are superior to those of P25, ZnO, TNTs and ZnO-anatase TiO2 (TNP) nanocomposite in the oxidation of rhodamine B under UV light irradiation. A comparison of the photocatalytic activities between different catalysts is discussed. Furthermore, we also find that the ZnO-TNT nanocomposite shows very favorable recycle use potential, because they have a high sedimentation rate and their photocatalytic activity is only slightly decreased even after five times of repeated uses.

[Using Fourier transform to analyse differential optical absorption spectrum].

According to the theory of differential optical absorption spectral technique, the differential optical absorption spectral monitoring equipment was designed. Aiming at two kinds of main pollutants, SO2 and NO2, in the atmosphere, this technique was used to monitor them. The present article puts forward the signal analysis method of Fourier transformation to process the above-mentioned two kinds of absorption spectra. The two approaches contain the removeal of noise and the fitting of the slow variety. On the frequency chart after the spectrum was transformed, the low frequency corresponded to the slow variety part and the high frequency corresponded to the noise part of the original spectrum, so through intercepting a certain frequency segment and using inverse Fourier transformation the slow variety part of the low frequency and the noise part of the high frequency of the absorption spectrum could be subtracted. After farther processing we can get a higher resolution differential absorption spectrum of the gas. According to the strength of the spectrum, we can calculate the concentration of the gas. After analysis and comparison with the conventional method, it is considered a new processing method of differential optical absorption spectral technique, and the method can fit the slow variety much better.

[Using Fourier transform to calculate gas concentration in DOAS].

Being an analysis tool of high sensitivity, high resolution, multicomponents, real-time and fast monitoring, the differential optical absorption spectrometry (DOAS) is becoming a new method in atmosphere pollution monitoring. In the DOAS technique, many gases spectra have periodicity evidently, such as those from SO2, NO, NH3 and NO2. Aiming at three kinds of main air-polluted gases, i.e., SO2, NO and NO2 in atmosphere, the DOAS technique is used to monitor them, and Fourier transform is used to analyse the above-mentioned absorption spectra. Under the condition of Hanning Windows, Fourier transforma is used to process various gases spectra which have periodicity. In the process, the value of the characteristic frequency has a linearity relation to the gas concentration. So a new analysis method of DOAS is proposed, which is utilizing the relation between the value of the characteristic frequency and the gas concentration to deduce a linearity formula to calculate the gas concentration. So the value of the characteristic frequency can be used to get the gas concentration. For the gases with evident spectrum periodicity, such as SO2 and NO, this method is good. But for some gases with periodicity not evident, the error in the calculated concentration is beyond the allowable value. So in this method, the important process is frequency separation. It is also the main part in the future study. In a word, this method frees itself from the basic theory in the DOAS technique, cuts down on the process of the concentration calculation and the spectral analysis, and deserves further study.

Running buffers for determination of chromium(VI)/(III), cobalt(II) and zinc(II) in complex matrices by capillary electrophoresis with contactless conductivity detection.

Complex matrices and rather high acidity in environmental samples are often the impelling challenges for the used running buffers of capillary electrophoresis. Twelve binary acid-base buffers were evaluated for separation of Cr(VI)/Cr(III), Co(2+) and Zn(2+) in a sample containing various salts by capillary electrophoresis with contactless conductivity detector. The malic acid (MA) systems including MA-His (histidine), MA-Arg (arginine) and MA-Tris (tris(hydroxymethyl)aminomethane) were selected as the candidates with powerful separation efficiency and good response sensitivity. In the MA-Tris buffer, optimization were further carried out in terms of the pH value and the concentration of MA, and the optimal conditions were obtained as 6mM MA-Tris and 2mM 18-crown-6 at pH 3.5. Furthermore, a real application was demonstrated by analyzing the plating rinse water (pH 0.8), in which the Ca(2+), Na(+), Cr(VI)/Cr(III), Co(2+) and Zn(2+) were all detected by adjusting at pH 3.5 with 5% (v/v) diluent ammonia. Both the cations, e.g., K(+), Ca(2+), Na(+), Mg(2+), and the common high concentration anions in the sample, e.g., Cl(-), SO(4)(2-) and NO(3)(-) did not cause any disturbance to the concerned analytes.

Epidemiological characteristics of expressway traffic trauma in 2040 cases.

OBJECTIVE: To evaluate the epidemiologic characteristics of expressway traffic trauma in 2040 cases in Zhejiang Province. METHODS: The data of 2040 cases of expressway traffic trauma taken from Zhejiang Provincial Expressway Traffic Bureau were analyzed with computer techniques. RESULTS: A total of 2040 persons were injured in 7963 expressway traffic accidents in Zhejiang Province from January 1999 to December 2001. Among them, 435 persons died (mortality, 21.3%) and 1 605 were injured. The economic losses were over 170 million yuan RMB. The accidents caused by human factors accounted for 84.9% (vehicle drivers accounting for 79.2%), which mainly included improper measures (20.4%), steering failure (17.7%), insufficient longitudinal space (15.9%), over-speed drive (12.5%), fatigue drive (6.4%), loading violation (5.9%) and careless drive (6.3%). Mechanical troubles and other factors took up 15.1%. There existed obvious uneven distribution among various regions. Jiaxing and Shaoxing were the sections with high incidence of accidents. The accidents mostly happened at 12:00-18:00, but the causing-dead ones most concentrated at 0:00-6:00. The main victims were young and middle-aged people (accounting for 72.3%), but accident-stricken children and elderly persons (over 70 years old) took up higher mortalities (30.2% and 40.7%, respectively). CONCLUSIONS: The number of expressway traffic accidents and the economic losses are increasing year by year, with obvious uneven distribution at different places, different time and under different weather conditions. To reduce the accident frequency, it is important to strengthen the enforcement of traffic regulation, to balance the system of "person-vehicle-road", and to improve the safety consciousness of people.