Spatiotemporal variations and source on black carbon over Chongqing, China: Long-term changes and observational experiments.

Black carbon (BC), as a critical light-absorbing constituent within aerosols, exerts profound effects on atmospheric radiation balance, climate, air quality and human health, etc. And it is also a long-standing focus in rapidly developing megacities. So, this study primarily focuses on investigating the variation characteristics and underlying causes of BC in Chongqing (31,914,300 population), which is one of the municipalities directly under the central government of China, serving as a pivotal economic hub in southwest China. Utilizing MERRA-2 reanalysis data, we examined the long-term changes of atmospheric BC over Chongqing 20 years (from 2002 to 2021). Moreover, BC mass concentration observations were conducted using an Aethalometer (AE-33) from March 15 to June 14, 2021 in Liangping District, Chongqing. The statistical analysis over the last 20 years reveals an annual mean BC concentration in Chongqing of 3.42 ± 0.20 µg/m3, exhibiting growth from 2002 to 2008, followed by a decline from 2008 to 2021. Monthly concentration displays a "U-shaped" trend, with the lowest values occurring in summer and the highest in winter. Due to topographical and meteorological influences, local emissions primarily contribute to BC pollution, characterized by a spatial distribution pattern of high in the west and low in the east. Ground observation indicates a distinct dual-peaked pattern in the diurnal variation of BC, with peak concentrations aligning with periods of high traffic emissions. The variation in BC is significantly influenced by meteorological conditions (wind, temperature, atmospheric boundary layer) and local pollution sources (predominantly traffic). Furthermore, extreme events analysis suggests that local emissions and regional transport (with higher contributions from Chongqing and the Sichuan Basin) predominantly contributed to BC pollution. This study effectively makes up for the deficiency in analyzing the distribution and sources of BC pollution in Chongqing, providing valuable scientific insights for the atmospheric environment of megacities.

Rational use of tigecycline and tigecycline blood concentration monitoring in patients with severe infection.

Tigecycline, a tetracycline antibiotic, is widely used against antimicrobial resistance; therefore, medical staff should use tigecycline rationally to improve clinical efficacy and reduce resistance to this drug. The present study aimed to enhance the rate of rational tigecycline usage. The patients were divided into a low-dose (50 mg tigecycline twice daily, every 12 h) and a high-dose group (100 mg twice daily, every 12 h). The blood concentrations of tigecycline were examined and the area under the curve (AUC)0-12 h values of the two groups were calculated. Prescriptions of tigecycline for 40 intensive care unit (ICU) cases were reviewed to evaluate the rationality of tigecycline usage. The peak plasma concentrations (the 7th administration after 1 h) of tigecycline were significantly higher in the high-dose group (2.46±0.43 µg/ml) compared with those in the low-dose group (1.25±0.16 µg/ml). The AUC0-12 h was 16.35±3.09 h µg/ml in the high-dose group and 9.83±1.23 h µg/ml in the low-dose group (P<0.001). There were 29 irrational prescriptions identified, involving: i) Lack of consultation records (n=20); ii) inappropriate usage or dosage (n=17); iii) inappropriate drug selection (n=2); or iv) lack of dynamic laboratory tests to evaluate the efficacy (n=4). The irrational use of tigecycline in ICU patients is common. The rate of rational tigecycline usage can be improved by strengthening the management, training and participation of clinical pharmacists.

[Protective effect and mechanism of Angong Niuhuang pill in sepsis-associated brain dysfunction of rats].

OBJECTIVE: To observe the protective effect of Angong Niuhuang pill on brain function of rats with sepsis, explore its protective mechanism, and provide the experimental basis for clinical application of Angong Niuhuang pill in the treatment of sepsis-associated encephalopathy (SAE). METHODS: Thirty male Sprague-Dawley (SD) rats were divided into sham operation group, sepsis model group and Angong Niuhuang pill group according to random number table method, with 10 rats in each group. The sepsis model was established by cecal ligation and puncture (CLP); rats in sham operation group received open and closed abdomen. The rats in the Angong Niuhuang pill group were given Angong Niuhuang pill (0.3 g/kg) by gastric irrigation daily for 3 days before CLP, and the drugs were administrated 12 hours after modeling again. After 24 hours of CLP, the neuroreflex scores were evaluated, white blood cell count (WBC), the levels of serum neuron-specific enolase (NSE) and S100ß were detected. Then the brain tissue was harvested. After hematoxylin-eosin (HE) staining, the pathological changes of brain tissue were observed under the light microscope. The mRNA expressions of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in brain tissue were detected by polymerase chain reaction. RESULTS: Compared with the sham operation group, the total score of neuroreflex scores in the sepsis model group and the Angong Niuhuang pill group were significantly reduced (4.43±1.40, 6.57±1.90 vs. 9.40±0.84, both P < 0.05), WBC, serum NSE, S100ß were significantly increased [WBC (×109/L): 8.07±1.32, 5.84±0.94 vs. 3.60±0.32; NSE (µg/L): 1.04±0.14, 0.61±0.07 vs. 0.16±0.04; S100ß (ng/L): 255.624±30.25, 97.72±15.41 vs. 46.88±12.03, all P < 0.05], and the mRNA expressions of IL-6 and TNF-α in brain tissue were significantly increased [IL-6 mRNA (2-ΔΔCt): 5.668±2.195, 3.605±1.014 vs. 0.997±0.329; TNF-α mRNA (2-ΔΔCt): 18.996±0.913, 1.746±0.710 vs. 0.674±0.132, all P < 0.05]. Compared with the sepsis model group, the total score of neuroreflex scores in the Angong Niuhuang pill group was significantly increased (6.57±1.90 vs. 4.43±1.40, P < 0.05), WBC, serum NSE, S100ß concentration, and the mRNA expressions of IL-6 and TNF-α in the brain were significantly reduced [WBC (×109/L): 5.84±0.94 vs. 8.07±1.32, NSE (µg/L): 0.61±0.07 vs. 1.04±0.14, S100ß (ng/L): 97.72±15.41 vs. 255.62±30.25, IL-6 mRNA (2-ΔΔCt): 3.605±1.014 vs. 5.668±2.195, TNF-α mRNA (2-ΔΔCt): 1.746±0.710 vs. 18.996±0.913, all P < 0.05]. Brain histopathological observation showed that the hippocampal neurons in the sepsis model group were disordered arrangement, a large number of neuronal nuclei were contracted, and the tissue was loose with obvious edema. Compared with the sepsis model group, the Angong Niuhuang pill group had less nuclear shrinkage and tissue edema. CONCLUSIONS: The pretreatment of the Angong Niuhuang pill can improve the brain dysfunction of septic rats and reduce the expression of pro-inflammatory cytokines in the brain. It is speculated that the Angong Niuhuang pill can protect the brain function in sepsis by inhibiting the inflammatory reaction in the brain.

[Design and application of Checklist for quality control in intensive care unit].

OBJECTIVE: To design a Checklist for quality control in intensive care unit and observe the effect of clinical application. METHODS: By consulting guidelines and literature, such as Critical care medicine professional medical quality control index (2015 edition), the quality control Checklist of intensive care unit was designed. It included four parts: quality control data collection, medical record quality verification, special diagnosis and treatment, and hospital infection prevention and control supervision. Every month, a doctor with a senior professional title served as the quality control director, and was responsible for the quality control of the department's medical care, including collecting data of the past 24 hours during the morning handover, discussing and registering special diagnosis and treatment behaviors that would be performed on the day, and coordinating with the nursing team leader, controlling the quality of the whole department throughout the day, such as supervising each medical staff if they had unreasonable behaviors, checking the running and discharge medical records, and inspecting the status of the staff on duty. The data in 2018, 2019 (Checklist implemented) and 2017 (Checklist not implemented) were retrospectively analyzed, including the status of admitted patients, department management information, length of intensive care unit (ICU) stay, and the incidence of three-tube infection [ventilator-associated pneumonia (VAP), catheter-related bloodstream infection (CRBSI), catheter-associated urinary tract infection (CAUTI)], and standardized mortality, etc. RESULTS: From 2017 to 2019, the number of patients admitted was 373, 446, and 480, with annual growth of 19.57% and 7.62% in 2018 and 2019, respectively, and an increase of 28.69% in 2019 compared with 2017. There was no statistically significant difference in the average age and acute physiology and chronic health evaluation II (APACHE II) of patients in the three years. Compared with 2017, the length of ICU stay of patients in 2018 and 2019 were significantly shortened (days: 8.99±6.12, 9.14±7.02 vs. 10.20±7.21), and the incidence of VAP, CRBSI and CAUTI were significantly reduced [VAP (cases/1 000 ventilation days): 12.97±3.60, 9.62±3.14 vs. 17.48±4.89, CRBSI (cases/1 000 catheter days): 3.75±2.19, 3.87±1.87 vs. 6.19±3.13, CAUTI (cases/1 000 catheter days): 3.29±2.18, 3.28±1.87 vs. 5.61±3.18]. The standardized mortality were also significantly reduced [(77.27±7.24)%, (70.61±7.49)% vs. (84.41±9.05)%], the number of non-compliance with hospital infection prevention per month decreased significantly (person times: 54.00±6.30, 41.08±10.76 vs. 72.08±19.68), and the number of special diagnosis and treatment per month increased significantly (person times: 1 056.67±235.27, 1 361.75±278.48 vs. 722.25±145.96), the rate of etiology submission before antimicrobial treatment [(93.21±3.68)%, (96.59±2.49)% vs. (87.86±5.28)%] and deep vein thrombosis (DVT) prevention rate [(91.13±6.36)%, (96.23±2.99)% vs. (85.58±7.68)%] were significantly improved, and all the differences were statistically significant (all P < 0.05). All medical records in the three years were Grade A, but the average scores in 2018 and 2019 were higher than those in 2017 (96.82±2.84, 96.73±2.94 vs. 93.70±3.33, both P < 0.01). Compared with 2018, the incidence of VAP, the rate of etiology submission before antimicrobial treatment, the DVT prevention rate, and the standardized mortality rate in 2019 were further improved, and the number of non-compliance with hospital infection prevention per month decreased and the number of special diagnosis and treatment per month increased, and the differences were statistically significant (all P < 0.05). CONCLUSIONS: The application of quality control Checklist in intensive care unit can build an effective quality control system, reduce the incidence of three-tube infection, standardized mortality and length of ICU stay, improve the quality control awareness and execution of medical staff, and promote the improvement of medical quality.

Relationships between soil respiration and hyperspectral vegetation indexes and crop characteristics under different warming and straw application modes.

Examining the relationship between seasonal variations in soil respiration and abiotic factors and vegetation indexes is crucial for modeling soil respiration using upscaled remote sensing satellite data. A field experiment including control (CK), warming (WA), straw application (SA), and warming and straw application (WASA) treatments was performed in a winter wheat-soybean rotation cropland on the north shore of the lower reaches of the Yangtze River. Soil respiration, abiotic factors, crop hyperspectral vegetation indexes, leaf area index (LAI), and chlorophyll content (represented as the SPAD value) were measured during the 2018-2020 rotation growing seasons. The results indicated that the mean annual soil respiration was 2.27 ± 0.04, 3.08 ± 0.06, 3.64 ± 0.08, and 3.95 ± 0.20 µmol m-2 s-1 in the CK, WA, SA, and WASA plots, respectively, during the 2-year experimental period. Soil respiration was significantly (P < 0.05) correlated with soil temperature, soil moisture, hyperspectral vegetation indexes, LAI, and SPAD value in all plots. Models that included temperature, moisture, hyperspectral vegetation indexes, LAI, and SPAD value explained 50.5-74.7% of the seasonal variation in soil respiration in the CK, WA, SA, and WASA plots during the 2-year experimental period. A model including the seasonal mean NDVI, DVI, EVI, PRI, and LAI explained 72.4% of the interseasonal and intertreatment variations in seasonal mean soil respiration in the different plots across the four different crop-growing seasons. Our study indicated the potential applicability of hyperspectral vegetation indexes, LAI, and SPAD value to the estimation of soil respiration at a regional scale.

Use of polymyxin B in patients with renal impairment: A retrospective examination of 5 cases.

In order to provide an idea dose of polymyxin B in Chinese patients with renal impairment, the present study collected the clinical data of all patients with renal impairment who received polymyxin B therapy in the intensive care unit (ICU) of The First Affiliated Hospital of Bengbu Medical College (Bengbu, China). The clinical data of six patients treated in the ICU between February 2018 and May 2019 were retrospectively analyzed. All patients had renal impairment and were treated with polymyxin B combination therapy. The patients in the current study received polymyxin B and carbapenem, or polymyxin, carbapenem, cefoperazon and sulbactam, or polymyxin B, carbapenems and aminoglycoside treatment. One patient discontinued treatment. The other five patients received polymyxin B at a dosage of 50 mg every 12 h (100 mg/day) through an intravenous drip. During treatment, four of the five patients had deteriorating renal function to varying degrees, and continuous renal replacement therapy (CRRT) was initiated. Polymyxin B was discontinued in all patients when the infection was controlled. After treatment, four of five patients showed improvement in renal function, and had normal kidney function at the 1-month follow-up evaluation, whereas one patient had chronic renal disease. During hospitalization, one patient experienced neurotoxicity, showing decreased limb muscle strength and cognitive impairment, which might have been caused by polymyxin B, according to the Naranjo adverse drug reactions probability scale (also known as the Naranjo algorithm) score. The present report demonstrated that the administration of 100 mg daily dosage of polymyxin B to the five patients weighing between 50 and 75 kg, could control pulmonary infection during the course of treatment of Chinese patients with renal impairment, however, further research is needed to verify this result. Risk factors for nephrotoxicity and neurotoxicity need to be fully assessed before initiating polymyxin B therapy in patients with renal impairment.

Price Competition and Product Differentiation Based on the Subjective and Social Effect of Consumers' Environmental Awareness.

Consumer environmental awareness (CEA) can affect green consumption decisions in different and confusing ways. In order to explain the reasons for these divergences, this study divides CEA into two main components: the subjective effect and the social effect. Then, we integrate the two effects into the classic Hotelling model to study the influence of CEA's subjective effect and social effect on price competition and product differentiation strategy. It was found that the subjective and social effects of CEA have opposite impacts on price competition and product differentiation strategies. The subjective effect of CEA increases the price and profit level of enterprises, and enlarges the difference in the environmental friendliness of products. Meanwhile, the social effect of CEA reduces the enterprises' price and profit level, and narrows the difference in the environmental quality of products. Therefore, we suggest that it is necessary for producers of green products to distinguish between these two effects. Numerical examples are provided to verify our findings. Finally, some possible suggestions regarding the competition of green products are put forward which take into consideration the subjective and social effects of CEA. The main contribution of this paper is to theoretically explain the opposite effects of the two different components of CEA on environmentally friendly product pricing and differentiation strategy; this presents a possible explanation as to why the behavior regarding CEA differs, and provides theoretical support for enterprises to price and differentiate green products.

[Changing laws of serum high mobility group box 1 protein in septic rats and the intervention effect of xuebijing].

OBJECTIVE: To investigate the changing laws of serum high mobility group box 1 protein (HMGB1) in septic rats and intervention effect of Xuebijing on it. METHODS: Lipopolysaccharide (LPS) (5 mg/kg BW) was intravenously injected into the tail vein of healthy male Wistar rats to prepare the sepsis rat model. In Experiment 1: 50 Wistar rats were randomly divided into three groups, i.e., the normal group (A, n=10); the LPS model group (B, n=10), the LPS +Xuebijing treatment group (C, n=30). Rats in the C group were further divided into three subgroups, i.e., 2 h before LPS injection (group C1), 2 h after LPS injection (group C2), and 8 h after LPS injection (group C3), 10 in each group. Blood samples were collected from the caudal vein to detect serum HMGB1 levels by Western blot at 4, 12, 24, 48, and 72 h after LPS injection. Experiment 2: 30 Wistar rats were equally divided into the LPS model group (D) and the LPS + Xuebijing treatment group (E), 15 in each group. They were treated as rats in the B group and the C1 group respectively. Five rats were sacrificed at 12, 24, and 48 h after LPS injection in the two groups. Blood as well as the tissue samples were harvested to measure such indices as ALT, AST, Cr, and BUN, as well as pathological changes of liver, lung, and kidney. RESULTS: (1) Compared with the A group, serum HMGB1 levels were higher at various time points in the B group (P < 0.05). Compared with the B group, serum HMGB1 levels at 12,24,48, and 72 h decreased in the C1, C2, and C3 groups. Besides, the decrease was more obvious at 24 h and 48 h.The decrement in the C3 group was less than that in the C1 and C2 groups (P < 0.05). (2) In the D group, ALT, AST, Cr, and BUN were significantly higher than those in the A group and reached the peak at 24 h (P < 0.05). Compared with the E group, AST, Cr, and BUN at 24 and 48 h, and ALT at each time point decreased significantly in the E group (P < 0.05). (3)The results of pathological section of liver, lung, and kidney showed local congestion and hemorrhage, cell edema/necrosis/degeneration, infiltration of inflammatory cells, damage of characteristic structures and so on; particularly serious lesion occurred at 24 and 48 h in the D group. The microscopic lesion was obviously alleviated in the E group than in the D group at corresponding time points. CONCLUSIONS: The serum HMGB1 levels increased in septic rats, with late occurrence of peak value and longer duration of the high value. HMGB1 played an important role in excessive inflammatory response and multiple organ dysfunction. Xuebijing could reduce the serum levels of HMGB1, improve biochemical parameters, and attenuate severe inflammatory response of liver, lung, and kidney tissues in septic rats. Besides, the earlier use, the better effect obtained.