Efficacy of Arthroscopy-Assisted Minimally Invasive Surgery in the Treatment of Patients with Tibial Plateau Fractures.

Objective: This study analyzes the therapeutic effect of arthroscopy-assisted minimally invasive surgery in patients with tibial plateau fractures (TPFs) and its influence on knee function and range of motion (ROM) recovery. Methods: This study enrolled 84 patients with TPFs admitted to the researchers' hospital between March 2021 and May 2022 as the study subjects, including 42 patients treated with open reduction and internal fixation (observation group) and 42 patients treated with arthroscopy-assisted minimally invasive surgery (experimental group). Then, perioperative indexes, knee symptom scores, knee function scores, knee ROM, and postoperative complications were compared between these two groups. Results: Surgery time was significantly shorter, intraoperative bleeding was less, and the time of the first off-bed activity was signally earlier in the experimental group than in the observation group (P < .05). All postoperative Lysholm and Rasmussen scores in both groups increased compared with preoperative scores, and the degree of increase was higher in the experimental group than in the observation group (P < .05). The range of flexion, extension, and internal/external rotation angles of patients was more extensive in both groups after surgery than before surgery, and the improvement of the experimental group was greater than that of the observation group (P < .05). The experimental group had a considerably lower incidence of postoperative complications than the observation group (P < .05). Conclusion: Arthroscopy-assisted minimally invasive surgery is highly effective in treating TPFs. Specifically, this surgery further improves knee symptoms, promotes the recovery of knee function, elevates knee ROM, and reduces the risk of postoperative complications compared to traditional open reduction and internal fixation.

Real-World Emission Characteristics of Full-Volatility Organics Originating from Nonroad Agricultural Machinery during Agricultural Activities.

Nonroad agricultural machinery (NRAM) emissions constitute a significant source of air pollution in China. Full-volatility organics originating from 19 machines under 6 agricultural activities were measured synchronously. The diesel-based emission factors (EFs) for full-volatility organics were 4.71 ± 2.78 g/kg fuel (average ± standard deviation), including 91.58 ± 8.42% volatile organic compounds (VOCs), 7.94 ± 8.16% intermediate-volatility organic compounds (IVOCs), 0.28 ± 0.20% semivolatile organic compounds (SVOCs), and 0.20 ± 0.16% low-volatility organic compounds (LVOCs). Full-volatility organic EFs were significantly reduced by stricter emission standards and were the highest under pesticide spraying activity. Our results also demonstrated that combustion efficiency was a potential factor influencing full-volatility organic emissions. Gas-particle partitioning in full-volatility organics could be affected by multiple factors. Furthermore, the estimated secondary organic aerosol formation potential based on measured full-volatility organics was 143.79 ± 216.80 mg/kg fuel and could be primarily attributed to higher-volatility-interval IVOCs (bin12-bin16 contributed 52.81 ± 11.58%). Finally, the estimated emissions of full-volatility organics from NRAM in China (2021) were 94.23 Gg. This study provides first-hand data on full-volatility organic EFs originating from NRAM to facilitate the improvement of emission inventories and atmospheric chemistry models.

Real-world emission characteristics of carbonyl compounds from agricultural machines based on a portable emission measurement system.

Emissions of carbonyl compounds from agricultural machines cannot be ignored. Carbonyl compounds can cause the formation of ozone (O3) and secondary organic aerosols, which can cause photochemical smog to form. In this study, 20 agricultural machines were tested using portable emission measurement system (PEMS) under real-world tillage processes. The exhaust gases were sampled using 2,4-dinitrophenylhydrazine cartridges, and 15 carbonyl compounds were analyzed by high-performance liquid chromatography. Carbonyl compound emission factors for agricultural machines were 51.14-3315.62 mg/(kg-fuel), and were 2.58 ± 2.05, 0.86 ± 1.07 and 0.29 ± 0.20 g/(kg-fuel) for China 0, China II and China III emission standards, respectively. Carbonyl compound emission factor for sowing seeds of China 0 agricultural machines was 3.32 ± 1.73 g/(kg-fuel). Formaldehyde, acetaldehyde and acrolein were the dominant carbonyl compounds emitted. Differences in emission standards and tillage processes impact ozone formation potential (OFP). The mean OFP was 20.15 ± 16.15 g O3/(kg-fuel) for the China 0 emission standard. The OFP values decreased by 66.9% from China 0 to China II, and 67.4% from China II to China III. The mean OFP for sowing seeds of China 0 agricultural machines was 25.92 ± 13.84 g O3/(kg-fuel). Between 1.75 and 24.22 times more ozone was found to be formed during sowing seeds than during other processes for China 0 and China II agricultural machines. Total carbonyl compound emissions from agricultural machines in China was 19.23 Gg in 2019. The results improve our understanding of carbonyl compound emissions from agricultural machines in China.

Chemical characterization of volatile organic compounds (VOCs) emitted from multiple cooking cuisines and purification efficiency assessments.

Cooking process can produce abundant volatile organic compounds (VOCs), which are harmful to environment and human health. Therefore, we conducted a comprehensive analysis in which VOCs emissions from multiple cuisines have been sampled based on the simulation and acquisition platform, involving concentration characteristics, ozone formation potential (OFP) and purification efficiency assessments. VOCs emissions varied from 1828.5 to 14,355.1 µg/m3, with the maximum and minimum values from Barbecue and Family cuisine, respectively. Alkanes and alcohol had higher contributions to VOCs from Sichuan and Hunan cuisine (64.1%), Family cuisine (66.3%), Shandong cuisine (69.1%) and Cantonese cuisine (69.8%), with the dominant VOCs species of ethanol, isobutane and n-butane. In comparison, alcohols (79.5%) were abundant for Huaiyang cuisine, while alkanes (19.7%), alkenes (35.9%) and haloalkanes (22.9%) accounted for higher proportions from Barbecue. Specially, carbon tetrachloride, n-hexylene and 1-butene were the most abundant VOCs species for Barbecue, ranging from 8.8% to 14.6%. The highest OFP occurred in Barbecue. The sensitive species of OFP for Huaiyang cuisine were alcohols, while other cuisines were alkenes. Purification efficiency assessments shed light on the removal differences of individual and synergistic control technologies. VOCs emissions exhibited a strong dependence on the photocatalytic oxidation, with the removal efficiencies of 29.0%-54.4%. However, the high voltage electrostatic, wet purification and mechanical separation techniques played a mediocre or even counterproductive role in the VOCs reduction, meanwhile collaborative control technologies could not significantly improve the removal efficiency. Our results identified more effective control technologies, which were conductive to alleviating air pollution from cooking emissions.

Aberrant expression of GSTM5 in lung adenocarcinoma is associated with DNA hypermethylation and poor prognosis.

BACKGROUND: Glutathione-S transferases (GSTs) comprise a series of critical enzymes involved in detoxification of endogenous or xenobiotic compounds. Among several GSTs, Glutathione S-transferases mu (GSTM) has been implicated in a number of cancer types. However, the prognostic value and potential functions of the GSTM family genes have not been investigated in lung adenocarcinoma (LUAD). METHODS: We examined the expression of GSTM5 in LUAD and identified associations among GSTM5 expression, clinicopathological features, survival data from the Cancer Genome Atlas (TCGA). The correlation between GSTM5 DNA methylation and its expression was analyzed using the MEXPRESS tool and UCSC Xena browser. The methylation status of GSTM5 in the promoter region in lung cancer cells was measured by methylation-specific PCR (MSP). After 5-aza-2'-deoxycytidine treatment of lung cancer cells, expression of GSTM5, cell proliferation and migration were assessed by RT-PCR, CCK-8 and transwell assays, respectively. RESULTS: The results showed that GSTM5 was abnormally down-regulated in LUAD patients' tissues, and patients with low GSTM5 expression level had significantly shorter OS. Cox regression analyses revealed that GSTM5 was associated with overall survival (OS) of LUAD patients, which expression was an independent prognostic indicator in terms of OS (hazard ratio: 0.848; 95% CI: 0.762-0.945; P = 0.003). In addition, we found the promoter region of GSTM5 was hypermethylated in the tumor tissue compared with adjacent normal tissues, and the average methylation level of GSTM5 were moderately correlated with its expression. Moreover, methylation-specific PCR also showed that the GSTM5 gene promoter was hypermethylated in lung cancer cells, and treatment with 5-Aza-CdR can restore the gene expression and inhibit cell proliferation and migration. Finally, Gene Set Enrichment Analysis (GSEA) revealed that low GSTM5 expression was significantly related to DNA repair pathways. CONCLUSION: Our data demonstrate that low GSTM5 expression and its high DNA methylation status may act as a novel putative molecular target gene for LUAD.

Reverse the down regulation of miR-92b-3p by hypoxia can suppress the proliferation of pulmonary artery smooth muscle cells by targeting USP28.

MiR-92b-3p has been shown to take part in several disease by regulate proliferation, apoptosis, differentiation and metastasis. However, the role of miR-92b-3p in pulmonary arterial hypertension (PAH) has not been illustrated clearly. Here, we found the level of miR-92b-3p which mainly located in the smooth muscle layer was down-regulation under hypoxic condition. It can inhibit pulmonary artery smooth muscle cells (PASMCs) proliferation and cell cycle progression. Through luciferase assay, miR-92b-3p bound to the 3'-UTR of USP28. we found that there was a significant negative relation between the level of miR-92b-3p and USP28 at protein level and reversed the down regulation of miR-92b-3p by hypoxia can suppress the proliferation of pulmonary artery smooth muscle cells by targeting USP28. These results suggested that miR-92b-3p acted a potential proliferation regulator in PASMCs and it maybe a novel treatment target of PAH.

Better rotational control but similar outcomes with the outside-in versus the transtibial drilling technique for anterior cruciate ligament reconstruction: a systematic review of comparative trials.

INTRODUCTION: This study was a systematic review comparing the clinical outcomes of using the transtibial (TT) versus the outside-in (OI) technique for anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: A comprehensive literature search was conducted using multiple databases, including Medline, Embase, and Cochrane. All databases were searched from the earliest records through August 2017 using the following Boolean operators: transtibial AND (outside-in OR out-in OR two incisions) AND anterior cruciate ligament. All prospective and retrospective controlled trials were retrieved that directly compared physical examination and knee function scores and patient-rated outcomes between the TT and OI techniques. RESULTS: Four prospective and three retrospective articles were identified by the search, and the findings suggested that the OI was superior to the TT technique for preparing the femoral tunnel based on the pivot shift test (p = 0.05). There was no statistically significant difference between the two treatment groups in International Knee Documentation Committee (IKDC) grades, IKDC scores, Lysholm scores, Tegner scores, or the Lachman test. CONCLUSIONS: No statistically significant differences were found in clinical functional results when comparing patients who underwent ACL reconstruction with the TT or OI techniques. However, the OI technique was found to be advantageous in conferring increased rotational stability as revealed by the pivot shift test. Additional studies with larger sample sizes are needed to make more precise conclusions. LEVEL OF EVIDENCE: Therapeutic study (systematic review), Level III.

Gastrodin causes vasodilation by activating KATP channels in vascular smooth muscles via PKA-dependent signaling pathway.

Gastrodin, one of the major components extracted from the Chinese herb Gastrodia elata Bl., has been widely used as an anticonvulsant, sedative, analgesic and hypotensive. In our study, we aimed to investigate the effects and possible mechanisms of gastrodin on vascular KATP channels. Tension experiments were used on rat mesenteric artery rings without an endothelium. Patch clamp experiments were executed to investigate the influences of gastrodin on the membrane current in mesenteric artery smooth muscle cells. Gastrodin induced vasorelaxation in a concentration dependent manner when rat mesenteric artery rings were pre-contracted with Phenylephrine. The vasorelaxation effect was partially diminished by pre-treating with a KATP channel inhibitor, or a PKA inhibitor. With whole-cell patch-clamp recording techniques, we found that gastrodin is a activator of KATP in rat mesenteric artery smooth muscle cells, and this effect was eliminate by pre-treating with H89or PKI, PKA inhibitor. In addition, when rat vascular smooth muscle cells were treated with 100 µM gastrodin for 24 h, maximum KATP current density increased by 28.1%. The results indicate that gastrodin exerts vasorelaxation effect through activation of PKA and subsequent opening of smooth muscle KATP channels.

Database of emission factors of volatile organic compound (VOC) species in motor vehicle exhaust in China.

The synergistic strategy for fine particulate matter (PM2.5) and O3 pollution prevention and control has emerged as a pivotal approach in combating air pollution. Volatile organic compounds (VOCs) serve as crucial precursors to both O3 and secondary organic aerosols (SOAs), with motor vehicles representing one of their significant sources. In this study, a standard for establishing a database of VOC species emission factors for motor vehicles was developed, and a database containing 134 VOC species was constructed through field tests and literature surveys. The VOC emissions of light-duty gasoline passenger vehicles (LDGPVs) comprised primarily alkanes and aromatics. The VOC emissions of light-duty diesel trucks (LDDTs) comprised mostly alkanes. Regarding low-speed trucks, 3-wheel vehicles, medium-duty diesel trucks (MDDTs) and heavy-duty diesel trucks (HDDTs), their VOC emissions comprised mainly oxygenated volatile organic compounds (OVOCs). The update of emission standards resulted in a reduction in VOC species emission factors while altering the composition of VOCs. Attention should be directed toward isopentane, benzene and dichloromethane emitted by LDGPVs, dodecane, undecane, ethene and propene emitted by LDDTs, and acetaldehyde emitted by HDDTs. VOC species originating from LDGPVs were more dispersed than those originating from LDDTs and HDDTs. In addition, variations in VOC species were observed among motor vehicles with different fuel types. Toluene, ethene, benzene, m,p-xylene, isopentane, hexanal, ethyne and 1,2,4-trimethylbenzene were the predominant VOC species emitted by gasoline vehicles. Diesel vehicles emitted mainly dodecane, formaldehyde, propene, undecane, acetaldehyde, ethene, decane and benzene. The results could enhance our comprehension of the emission characteristics of VOC species originating from motor vehicles and provide data support and a scientific foundation for achieving synergistic PM2.5 and O3 pollution prevention and control.

Efficacy Study of Multidisciplinary Team Participating in the Perioperative Administration for Elderly Patients With Intertrochanteric Fractures: A Prospective Randomized Controlled Trail.

OBJECTIVE: To evaluate the efficacy of the multidisciplinary team (MDT) participating in the perioperative administration and 1-year follow-up for elderly patients with intertrochanteric fractures. METHOD: Elderly patients who underwent surgical treatment of intertrochanteric fractures in our hospital, from January 2018 to December 2020, were taken as the research object. According to the inclusion and exclusion criteria, a total of 76 patients were prospectively included and equally allocated to form a MDT group and a conventional group in this trial by the random number table method. The MDT was composed of doctors from nine disciplines, who would work jointly to evaluate the perioperative risk and formulate the treatment plan and the rehabilitation program. RESULTS: Compared with the conventional group, the time before weight-bearing (59.93 ± 5.93 days vs 67.93 ± 5.87 days), fracture healing time (68.98 ± 7.82 days vs 78.91 ± 7.09 days), and the length of hospital stay (10.43 ± 2.01 days vs 13.87 ± 2.13 days) in the MDT group were all shorter, P < 0.001, and the VAS declined from 3.18 ± 0.81 to 2.28 ± 0.87 at 3 days after the operation and from 0.26 ± 0.04 to 0.23 ± 0.03 at 3 months after the operation in the MDT group, P < 0.001. Compared with the only case in the MDT group which had postoperative complications, postoperative complications were more common in the conventional group, and the difference was statistically significant, P = 0.025. At 1 month and 1 year after the operation, the Harris hip score results of the MDT group were all higher in the seven aspects than those in the conventional group; the difference was statistically significant ( P < 0.001). CONCLUSION: The MDT participated in the perioperative management and the guidance of postoperative rehabilitation of elderly patients with intertrochanteric fractures can markedly improve perioperative symptoms, promote postoperative recovery, and improve long-term hip joint function.

Effects of mesencephalic astrocyte-derived neurotrophic factor on sepsis-associated acute kidney injury.

BACKGROUND: To determine the protective role of mesencephalic astrocyte-derived neurotrophic factor (MANF) in regulating sepsis-associated acute kidney injury (S-AKI). METHODS: A total of 96 mice were randomly divided into the control group, control+MANF group, S-AKI group, and S-AKI+MANF group. The S-AKI model was established by injecting lipopolysaccharide (LPS) at 10 mg/kg intraperitoneally. MANF (200 µg/kg) was administered to the control+MANF and S-AKI+MANF groups. An equal dose of normal saline was administered daily intraperitoneally in the control and S-AKI groups. Serum and kidney tissue samples were obtained for biochemical analysis. Western blotting was used to detect the protein expression of MANF in the kidney, and enzyme-linked immunosorbent assay (ELISA) was used to determine expression of MANF in the serum, pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]). Serum creatinine (SCr), and blood urea nitrogen (BUN) were examined using an automatic biochemical analyzer. In addition, the kidney tissue was observed for pathological changes by hematoxylin-eosin staining. The comparison between two groups was performed by unpaired Student's t-test, and statistics among multiple groups were carried out using Tukey's post hoc test following one-way analysis of variance (ANOVA). A P-value <0.05 was considered statistically significant. RESULTS: At the early stage of S-AKI, MANF in the kidney tissue was up-regulated, but with the development of the disease, it was down-regulated. Renal function was worsened in the S-AKI group, and TNF-α and IL-6 were elevated. The administration of MANF significantly alleviated the elevated levels of SCr and BUN and inhibited the expression of TNF-α and IL-6 in the kidney. The pathological changes were more extensive in the S-AKI group than in the S-AKI+MANF group. CONCLUSION: MANF treatment may significantly alleviate renal injury, reduce the inflammatory response, and alleviate or reverse kidney tissue damage. MANF may have a protective effect on S-AKI, suggesting a potential treatment for S-AKI.

Real-world emission characteristics of semivolatile/intermediate-volatility organic compounds originating from nonroad construction machinery in the working process.

Detailed emission characterization of semivolatile/intermediate-volatility organic compounds (S/IVOCs) originating from nonroad construction machines (NRCMs) remains lacking in China. Twenty-one NRCMs were evaluated with a portable emission measurement system in the working process. Gas phase S/IVOCs were collected by Tenax TA tubes and analyzed via thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Particle phase S/IVOCs were collected by quartz filters and analyzed via GC-MS. The average emission factors (EFs) for fuel-based total (gas + particle phase) IVOCs and SVOCs of the assessed NRCMs were 221.45 ± 194.60 and 11.68 ± 10.67 mg/kg fuel, respectively. Compared to excavators, the average IVOC and SVOC EFs of loaders were 1.32 and 1.55 times higher, respectively. Compared to the working mode, the average IVOC EFs under the moving mode (only moving forward or backward) were 1.28 times higher. The IVOC and SVOC EFs for excavators decreased by 69.06% and 38.37%, respectively, from China II to China III. These results demonstrate the effectiveness of emission control regulations. In regard to individual NRCMs, excavators and loaders were affected differently by emission standards. The volatility distribution demonstrated that IVOCs and SVOCs were dominated by gas- and particle-phase compounds, respectively. The mode of operation also affected S/IVOC gas-particle partitioning. Combined with previous studies, the mechanical type significantly affected the volatility distribution of IVOCs. IVOCs from higher volatile fuels are more distributed in the high-volatility interval. The total secondary organic aerosol (SOA) production potential was 104.36 ± 79.67 mg/kg fuel, which originated from VOCs (19.98%), IVOCs (73.87%), and SVOCs (6.15%). IVOCs were a larger SOA precursor than VOCs and SVOCs. In addition, normal (n-) alkanes were suitably correlated with IVOCs, which may represent a backup solution to quantify IVOC EFs. This work provides experimental data support for the refinement of the emission characteristics and emission inventories of S/IVOCs originating from NRCMs.

Real-world emission characteristics and inventory of volatile organic compounds originating from construction and agricultural machinery.

Volatile organic compound (VOC) emissions originating from nonroad mobile sources constitute an important but uncertain source of secondary organic aerosols (SOAs) and ozone (O3). In this study, we investigated the emission factors (EFs) of 120 individual VOC species for 40 machines via gas chromatography-mass spectrometry/flame ionization detection and high-performance liquid chromatography. The results showed that the diesel-based VOC EF for the tested machines was 4.18 ± 2.55 (average ± standard deviation) g/kg fuel, dominated by alkanes (38.20 % ± 18.08 %) and oxygenated VOCs (OVOCs; 30.94 % ± 15.71 %). The machine type, rated power, emission standards, and operating conditions affected the emissions of VOCs and their components, and this effect maybe mostly depends on the fuel combustion efficiency. The VOC species were primarily distributed in the C1-C2 and C4-C6 (based on the carbon number) and B4-B6 (based on the saturated vapor concentration) intervals. Furthermore, the estimated formation potential (FP) values of SOAs and O3 from VOCs were 21.02 ± 15.57 mg/kg fuel and 15.96 ± 11.87 g/kg fuel, respectively. VOC control based on the SOA formation potential (SOAFP) and ozone formation potential (OFP) could be more effective in the mitigation of fine particulate matter (PM2.5) and O3 pollution because the top 5 species ranked by percentage contribution accounted for 83.09 % ± 9.59 % and 51.78 % ± 14.38 % of the estimated SOAFP and OFP, respectively. Finally, the emission estimates showed that the VOC emissions originating from construction and agricultural machinery in China (2020) reached 64.05 and 95.24 Gg, respectively. We provide species-specific VOC EFs and detailed emission characteristics to facilitate a comprehensive understanding of gas emissions originating from nonroad mobile sources and an update of emission inventories and atmospheric chemistry models.

Reciprocal regulation of HIF-1α and 15-LO/15-HETE promotes anti-apoptosis process in pulmonary artery smooth muscle cells during hypoxia.

15-Hydroxyeicosatetraenoic acid, a predominant metabolic product of arachidonic acid (AA) catalyzed by 15-lipoxygenase (15-LO), plays an important role in hypoxic pulmonary arterial hypertension (PAH). Hypoxia-inducible factor-1α (HIF-1α) as a critical oxygen-sensitive transcriptional factor participates in many physiological and pathological processes including PAH. Therefore, it is possible that there may be some connections between HIF-1α and 15-LO/15-HETE in hypoxic pulmonary artery smooth muscle cells. Our results showed that HIF-1α inhibitor or siRNA reduced hypoxia-induced upregulation of 15-LO and endogenous 15-HETE, meanwhile HIF-1α expression and transcriptional activity were induced by 15-HETE under both normoxic and hypoxic conditions. It suggests there exists a potential positive feedback regulatory loop between HIF-1α and 15-LO/15-HETE. Furthermore, cell viability assay and several cell apoptosis assays, including TUNEL assay, Western blot, nuclear morphology determination, mitochondrial potential analysis, indicated that blocking HIF-1α induced apoptosis, decreased cell viability and suppressed the anti-apoptosis effects of 15-HETE. Taken together, our data indicate that upregulation of 15-LO/15-HETE in response to hypoxia may be partially mediated by HIF-1α which is also regulated by 15-HETE in a positive feedback manner, and HIF-1α can effectively inhibit pulmonary artery smooth muscle cells apoptosis which leads to vascular remodeling. The feedback loop between HIF-1α and 15-LO/15-HETE would obviously reinforce hypoxia-induced anti-apoptosis effect and may become a novel target of therapy in PAH.

Multi-type emission factors quantification of black carbon from agricultural machinery based on the whole tillage processes in China.

Black carbon (BC), as one of the short-lived climate pollutants, is becoming more prominent contribution from non-road mobile source, especially for agricultural machinery (AM) in China. However, the understanding of BC emissions from AM is still not clear, and the BC emission factors (EFs) are also limited. In this study, we conducted real-world measurements on twenty AM to investigate the instantaneous BC emission characteristics and quantify BC EFs under the whole tillage processes. We find the instantaneous BC emissions and fuel consumptions are obvious differences and present good synchronization under different tillage processes. Multi-type (CO2-, fuel-, distance-, time-, and area-based) EFs of BC are developed, which are significantly affected by different tillage processes and emission standards of the used AM. While AM conducting rotary tillage, ploughing, harvest corn and harvest wheat on the same area of land, total BC emissions by using the China III emission standard AM will be reduced by 56%, 36%, 88%, and 87% than those by using China II emission standard AM, respectively. Furthermore, for corn and wheat production under the whole tillage processes, BC EFs are 16.90 (6.03-39.12) g/hm2 and 18.18 (5.91-38.69) g/hm2, CO2 EFs are 112.64 (72.07-195.98) g/hm2 and 103.72 (71.47-167.02) g/hm2, respectively. We estimate the BC and CO2 emissions from wheat and corn productions based on the average area-based EFs. The large fluctuation ranges of BC and CO2 emissions in different tillage processes and the whole processes can reflect that the use of AM in China is uneven. It also indicates that there is a large space for BC and CO2 emission reduction and optimization. Therefore, more attention should be paid to the control of BC and CO2 emissions from AM. We believe that the recommended multi-type EFs are applicable for the quantification of BC emissions from AM in China and other countries.

Quantitative of instantaneous BC emissions based on vehicle specific power from real-world driving diesel trucks in China.

In-depth exploration of the potential links between instantaneous black carbon (BC) emissions and driving parameters from real-world diesel trucks (DTs) is a key step toward development of a highly flexible vehicle emissions estimation system. In this study, we conducted real-world measurements on 22 DTs with mainstream types and emission standards, and obtained instantaneous data of BC emissions and vehicle driving. Since vehicle specific power (VSP) is an excellent surrogate for engine load, we characterize the instantaneous BC emissions and VSP distributions, and then establish links between VSP and fuel consumption, VSP and BC emission rates, VSP and BC emission factors (EFs), respectively. We find that BC emission rates of China V light-duty DTs installed with diesel particulate filter (DPF) are significantly lower (2 to 3 orders of magnitude) than those with China III and China IV. Frequent acceleration and deceleration of vehicles maybe the main reason leads to high BC emissions. The distribution of VSP is mainly concentrated in the ranges of -30 to 35 kW/t in the scope of this study. We find that VSP and BC EFs did not show a consistent pattern for all tested DTs, and BC EFs present obvious fluctuations with the VSP variation. The average fuel-based BC EFs vary by factors of 2.27-8.25 from the lowest to highest EFs. Through a fitting of the third-order polynomial function, we finally quantify and provide fitting formulas of BC EFs and VSP under more detailed categorization. Our results can provide important data support for accurate quantification of BC EFs, and even emission inventory calculations.

Multi-pollutant emission characteristics of non-road construction equipment based on real-world measurement.

Non-road construction equipment (NRCE) has become a crucial contributor to urban air pollution. However, the current research on NRCE is still in its infancy, and the understanding of its pollutant emissions is not yet clear. In this study, multi-pollutant (CO, HC, NOx, PM2.5, and BC) and CO2 emissions from 12 excavators and 9 loaders under real-world conditions are investigated by using a synchronous platform based on portable emission measurement system (SP-PEMS). We find the instantaneous emission rates of multi-pollutant present significant variability under different operation modes, and pollutant emissions are significantly high under cold start. Generally, multi-pollutant emission factors (EFs) have been all effectively reduced with the tightening of emission standards except for CO and NOx. The BC and PM2.5 emissions are significantly affected by engine types, and those emitted by electronically-controlled fuel injection (EI) engines are at lower concentration levels compared with mechanical fuel injection (MI) engines. The mass ratios of BC/PM2.5 for EI engines are 2.05 times that for MI engines on average. Through comparison, we find the multi-pollutant EFs of NRCE reported by different studies and the Guide vary greatly, and those recommended by the Guide may be overestimated or underestimated to varying degrees. Finally, we recommend the multi-pollutant EFs of NRCE under different emission standards by combining the results of various studies, and which will provide scientific support for the accurately establish of emission inventory.

Non-negligible emissions of black carbon from non-road construction equipment based on real-world measurements in China.

Non-road construction equipment (NRCE) has become a vital contributor to urban air pollutants with the rapid urbanization in China. Black carbon (BC), as a key pollutant emitted from NRCE (mainly diesel-fueled), has attracted considerable concerns due to adverse impacts on climate change, visibility, and human health. However, the understanding of its emissions is still unclear based on limited research results. In this study, we conducted real-world measurements on BC emissions from 12 excavators and 9 loaders to characterize the variation and quantify fuel-based emission factors (EFs) by using a synchronous platform based on PEMS (SP-PEMS). We analyzed the impacts of key factors (operation mode, emission standard, and engine rated power) on BC emission comprehensively. High BC emission in working mode may be mainly owing to the increase of fuel consumption and the deterioration of air-fuel ratio. With more stringent emission standards, BC EFs of all tested NRCE present significant decreasing trends. Interestingly, NRCE with high rated power generally exhibits lower BC emissions. Through comparison, we find BC EFs in this study are generally higher than elemental carbon (EC) EFs reported in previous studies, which will lead BC emissions from NRCE to be underestimated while EC EFs are used instead of BC EFs. Furthermore, BC EFs of NRCE with Stage III are significantly higher (1-3 orders of magnitude) than those of on-road diesel trucks with the current mainstream emission standards of China IV and China V, which reinforces the urgency and importance of controlling BC emissions from NRCE in China. Finally, we recommend BC EFs of excavators and loaders under different emission standards and operation modes, and which preliminarily fills the gap in localized BC EFs of typical NRCE to relieve the urgent needs for emission inventory calculation.

Polycyclic and nitro-polycyclic aromatic hydrocarbon pollution characteristics and carcinogenic risk assessment of indoor kitchen air during cooking periods in rural households in North China.

Medium-flow atmospheric samplers were used to collect particulate (PM2.5) and gaseous samples from the indoor kitchen of each of 35 randomly selected rural houses in North China while a meal was being cooked. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) and 9 nitro-PAHs (NPAHs) in the samples were quantified by high-performance liquid chromatography (HPLC). This study provided the real PAH and NPAH pollution characteristics and carcinogenic risk produced by cooking in rural indoor kitchens in North China. The mean PAH and NPAH concentrations in air in the indoor kitchens during cooking periods were 4049.1 and 1741.6 ng/m3, respectively. The PAH and NPAH concentrations were lower in the particulate phase than the gaseous phase. The mean PAH and NPAH concentrations were much higher for cooking using coal than for cooking using liquefied petroleum gas (LPG) or electricity. The PAH and NPAH benzo[a]pyrene toxic equivalent (TEQBaP) concentrations for cooking using coal were 1823.3 and 2760.9 ng/m3, respectively. Lower PAH and NPAH concentrations were found in kitchens with than without range hoods. Range hoods decreased the PAH and NPAH TEQBaP concentrations by 68.8% and 61.9%, respectively. Appropriate fuel and ventilation choice will improve air pollution in indoor kitchens during cooking. The results provide important evidence for changing cooking habits and developing policies for cooking in rural China.