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Multimorbidity has become one of the most pressing public health concerns worldwide. The objectives of this study were to understand the prevalence of multimorbidity and its relationship with lifestyle factors among Chinese adults in Macau, and to investigate the combined contribution of common lifestyle factors in predicting multimorbidity. Data were collected through face-to-face interviews using a self-reported questionnaire on common chronic diseases, lifestyle factors and sociodemographics. BMI, physical activity, drinking status, smoking status and sleep quality were assessed, and a composite lifestyle score (0 to 9 points) was calculated, and the higher the score, the healthier the lifestyle. A total of 1443 participants were included in the analysis, of whom 55.2% were female, 51.8% were middle aged or elderly and 30.5% completed tertiary education or higher. The prevalence of multimorbidity was 10.3%. The combination of hypertension and hyperlipidaemia was the most common (22.2%) multimorbidity among the participants with multimorbidity. After the adjustment of the covariates, it was found that the participants who were overweight (OR: 1.95, 95% CI: 1.18–3.20, p = 0.009) or obese (OR: 3.76, 95% CI: 2.38–5.96, p < 0.001), former drinkers (OR: 2.43, 95% CI: 1.26–4.69, p = 0.008), and those who reported poor sleep quality (OR: 2.25, 95% CI: 1.49–3.40, p < 0.001) had a high risk of developing multimorbidity. A one-unit increase in the lifestyle score was associated with a 0.33-times reduction in the risk of developing multimorbidity (OR: 0.67; 95% CI: 0.59–0.77, p < 0.001). A combination of lifestyle factors can influence a variety of multimorbidity among the Chinese adults in Macau. Thus, comprehensively assessing the combined contribution of several lifestyle factors in predicting multimorbidity is important.

Pressure ulcer (PU) is a common type of chronic wound that is difficult to treat. Platelet-rich plasma (PRP) is rich in cytokines and growth factors, and it can be divided into two categories according to its leukocyte content: leukocyte-poor PRP (P-PRP) and leukocyte-rich PRP (L-PRP). PRP has been applied in a variety of wound treatments, due to its strong ability to promote repair. This study aims to investigate the therapeutic effects of PRP on PU and elucidate the role of leukocytes in the treatment process. Sprague-Dawley rats were used to establish PU models of ischemia–reperfusion injury by applying magnets externally. L-PRP, P-PRP, and saline were injected into the dermal wounds. Wound healing analysis and sampling were performed on days 3, 7, 11, and 15 after treatment. Histological examinations, real-time PCR, immunohistochemical examinations, and biomechanical assay were carried out on the wound samples. The PRP groups exhibited greater wound inflammatory response than the control group in the early stage but the response reduced rapidly as the wound healed. On days 7, 11, and 15, the PRP groups also yielded better wound healing rates and histological outcomes than the control group, with superior biomechanical properties observed on day 15. Among both PRP groups, the L-PRP group attained a higher wound healing rate than the P-PRP group on day 7, with greater significant early inflammatory responses, and more prominent angiogenesis. Therefore, PRP is proven to accelerate the healing of PU, with L-PRP being more effective in regulating inflammation and promoting angiogenesis than P-PRP.

Intra-articular injection is frequently used as an effective diagnostic and treatment tool for hip joint diseases. However, the underlying treatment mechanism remains unclear because of a lack of experimental animal models. A challenge facing researchers is how to accurately and consistently perform injections involving animal hip joints. The purpose of this study, then, was to establish an ultrasound (US)-guided intra-articular (IA) injection technique using rat hip joints and to evaluate its accuracy and feasibility versus a fluoroscopy (FL)-guided technique. For this study, 20 US-guided and 20 FL-guided IA injections were administered to separate groups of Sprague-Dawley rats. For each procedure, 50 μL of iohexol was injected into the hip joint using a 25G needle. The US-guided injections were performed using a linear probe, and the FL-guided IA injections were performed using C-arm X-ray fluoroscopy. All injections were verified by computed tomography imaging. The number of successful injections and needle repositions per injection, as well as operating times, were recorded, and the rats were observed for complications for 10 d after the injections. Statistical analysis was used to compare US-guided and FL-guided techniques with significance set at p < 0.05. The success rate was markedly higher for the US-guided interventions (90%) than for the FL-guided interventions (75%) (p

During the last 50 ka, cryogenic wedges on the Ordos Plateau formed during three major periods: (i) early local Last Glaciation, ca. 50 ka BP; (iii) local Last Permafrost Maximum(local LPM), 25–19 ka BP; and (v) post-local LPM, 16–9 ka BP. Cryoturbations mainly formed in the following periods: (ii) pre-local LPM, 45–30 ka BP and (iv) ~ 20 ka BP. The coldest periods with well-developed permafrost (i and iii) were most conducive for forming cryogenic wedges. The following periods of warming climate and degrading permafrost favored the formation of cryoturbations. During the local LPM, sand wedges and polygons were well developed and widely distributed on the Ordos Plateau when mean annual air temperatures (MAATs) were approximately 12°C lower than that at present. At ~30 ka BP, MAAT was 6–7°C lower than that at present. Paleoclimate conditions on the Ordos Plateau were reconstructed since 50 ka BP as follows: cold (ca. 50 ka BP) → cool (45–30 ka BP) → very cold (25–19 ka BP) → cool (19–9 ka BP) → intermittent warming until the present day. The amount of precipitation fluctuated, but with a general trend of drying since 50 ka BP. Under the next generally warming climate (after 9 ka BP), permafrost gradually degraded and eventually disappeared from the Ordos Plateau.

Weiqi Liu,1,* Weiling Liu,2,* Shaoling Wang,3 Huichun Tong,4 Jianmin Yuan,5 Zhenning Zou,6 Jianwen Liu,7 Donghai Yang,8 Zhongxing Xie9 1Department of Clinical Laboratory, Maternal and Children Health Care Hospital (Huzhong Hospital) of Huadu, Guangzhou, Guangdong, 510800, People’s Republic of China; 2Department of Clinical Laboratory, Chancheng Centre Hospital, Foshan, Guangdong, 528000, People’s Republic of China; 3Department of Clinical Laboratory, Taishan People’s Hospital, Jiangmen, Guangdong, 529200, People’s Republic of China; 4Department of Clinical Laboratory, Boai Hospital of Zhongshan, Zhongshan, Guangdong, 528402, People’s Republic of China; 5Department of Clinical Laboratory, Humen Hospital, Dongguan, Guangdong, 523899, People’s Republic of China; 6Department of Clinical Laboratory, Shenzhen Maternity & Child Healthcare Hospital, Shenzhen, Guangdong, 518028, People’s Republic of China; 7Department of Clinical Laboratory, Huiyang Sanhe Hospital, Huizhou, Guangdong, 516211, People’s Republic of China; 8Department of Clinical Laboratory, Sanzhao Town Health Center, Jinwan District, Zhuhai, Guangdong, 519040, People’s Republic of China; 9Department of Clinical Laboratory, The Second People’s Hospital of Zhaoqing, Zhaoqing, Guangdong, 526060, People’s Republic of China*These authors contributed equally to this workCorrespondence: Shaoling Wang Email shaoling_w@hotmail.comBackground: In China, the prevalence of HUA in the Pearl River Delta (PRD) region of Guangdong Province has not been extensively investigated. Therefore, this study investigated the prevalence of HUA and its related factors among people aged 20– 99 years in nine cities in the PRD.Materials and Methods: We selected 6491 health check participants from 9 cities in the PRD and collected participants’ anthropometric and biochemical test results for a cross-sectional study. We included 6491 participants and assessed their blood pressure (BP), body mass index (BMI), total cholesterol (TC), triglycerides (TG), glucose (Glu) and serum uric acid (UA) to analyze the regional prevalence of HUA and its related factors. HUA was indicated when fasting serum UA level was > 420 μmol/L in men and > 360 μmol/L in women.Results: Overall prevalence of HUA in our cohort was 34.05%; prevalence was higher in men than in women (41.53% vs 26.14%, P < 0.001). Characteristics associated with HUA were hypertension (odds ratio (OR), 5.506; 95% confidence interval (CI), 4.402– 6.889), higher body mass index (BMI; OR: 1.746; 95% CI: 1.560– 1.954), age 31– 40 years (OR: 0.829; 95% CI: 0.706– 0.973), age 61– 70 years (OR: 1.434; 95% CI: 1.194– 1.722) and age ≥ 71 years (OR: 1.742; 95% CI: 1.397– 2.173). In all subjects, serum UA was positively correlated with Glu, TG and TC. After we adjusted for age, BMI and BP, multivariate logistic regression analysis showed that HUA risk factors were high TC (OR: 1.770; 95% CI: 1.459– 2.147) and TG (OR: 1.961; 95% CI: 1.632– 2.357) in men; and high Glu (OR: 1.508; 95% CI: 1.084– 2.099), TC (OR: 1.341; 95% CI: 1.084– 1.660) and TG (OR: 1.680; 95% CI: 1.290– 2.187) in women.Conclusion: The prevalence of HUA was relatively high in the PRD of Guangdong Province. Relevant governmental bodies should focus on early diagnosis, early treatment and early intervention.Keywords: hyperuricemia, uric acid, prevalence, cardiovascular diseases, risk

The framework of Quaternary permafrost in China was reconstructed for the first time on the basis of available periglacial, glacial, and other proxies. During the Early Pleistocene (2.68–0.80 Ma BP), permafrost advanced southwards to 47–50◦ N in northern China and possibly occurred in alpine regions in western China. During the Middle Pleistocene (800–130 ka BP), permafrost occurred extensively on the Qinghai-Tibet Plateau (QTP) and in alpine or mountainous regions of northern, western, central, and northeastern China. The Great Interglacial occurred afterward and before the Last Glaciation, but the evidence of permafrost for this period has been seldom found. Permafrost evolution of the Last Glaciation (72–19 ka BP) in China is divided into: Expansion (72~50 ka BP), degradation (50–26 ka BP), and intensive expansion during the Last Permafrost Maximum (LPMax, 26–19 ka BP) with a permafrost extent of 5.3 × 106~5.4 × 106 km2, and when major features of present permafrost took shape. Permafrost fluctuated during the Younger Dryas (12.9–11.7 ka BP). Since the Holocene, permafrost in China expanded and retreated to lesser extents, forming the current permafrost environment. The Holocene evolution of permafrost was divided into: Unstable climate but stable permafrost during the early Holocene (11.7~8.5–7.0 ka BP); permafrost degradation during the Last Permafrost Minimum (LPMin, or the Holocene Megathermal; 8.5–7.0~4.0–3.0 ka BP) and the Medieval Warm Period (MWP; 1.0~0.5 ka BP); permafrost expansion during the Neoglaciation (4.0–3.0~1.0 ka BP) and the Little Ice Age (LIA; 0.5~0.1 ka BP); and recent permafrost degradation (20th century to the present). However, this review paper only provides the framework of Quaternary permafrost in China and some preliminary discussions. Many key questions await further investigations.

Shuo Luan,&ast; Shaoling Wang,&ast; Caina Lin, Shengnuo Fan, Cuicui Liu, Chao Ma, Shaoling Wu Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, SunYat-sen University, Guangzhou, 510120, Guangdong, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Shaoling Wu; Chao Ma, Email wushl@mail.sysu.edu.cn; machao@mail.sysu.edu.cnBackground and Objective: Osteonecrosis of the femoral head (ONFH) is a devastating disease, and there is some evidence that extracorporeal shock wave therapy (ESWT) and intra-articular platelet-rich plasma (PRP) injection might alleviate pain and improve joint function in individuals with ONFH. The objective of this study was to compare the effectiveness and safety of PRP and ESWT in symptomatic ONFH patients.Methods: A total of 60 patients aged 40– 79 with unilateral ONFH at Association Research Circulation Osseous (ARCO) stages I, II, and III were randomly assigned to the PRP (N=30) or the ESWT group (N=30). Four treatment sessions were provided in both groups. Assessments were performed at baseline, and 1-, 3-, 6-, and 12-month. Primary outcomes were measured by the visual analogue scale (VAS), and pressure pain thresholds (PPTs). Secondary outcomes were assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score (HHS), and magnetic resonance imaging (MRI). The linear mixed-model analysis was used to evaluate the differences between groups and within groups and the “group by time” interaction effects.Results: There were significant differences between groups in terms of changes over time for VAS, PPTs, WOMAC, and HHS since 3-month and maintained up to 12-month (P< 0.05, except for PPTs at 12-month). The simple main effects showed that the patients in PRP group had greater improvements in VAS (mean difference = − 0.82, 95% CI [− 1.39, − 0.25], P=0.005), WOMAC (mean difference = − 4.19, 95% CI [− 7.00, − 1.37], P=0.004), and HHS (mean difference = 5.28, 95% CI [1.94, 8.62], P=0.002). No related adverse events were reported.Conclusion: This study supported the effectiveness and safety of both the PRP injection and ESWT in treating ONFH patients. For symptomatic patients with ONFH, intra-articular PRP injection appeared superior to ESWT in pain relief and functional improvement.Keywords: necrosis of the femoral head, platelet-rich plasma, ultrasound-guided intra-articular injection, extracorporeal shock wave therapy

Plasmid-mediated, transmissible, tigecycline-inactivating enzyme Tet(X) has attracted considerable public attention. However, so far studies have not addressed its impact on public health and the ecosystem. Herein, we report the prevalence and molecular epidemiology of tet(X)-positive bacteria (TPB) from diverse sources, investigate the host-specificity of TPB and the transferability of tet(X). Sample collection was conducted between 2018 and 2020 in 30 provinces in China. PCR screening suggested tet(X) was prevalent among freshwater fishes (24.7%, 95% CI 19.4–30.7%), followed by chickens (23.6%, 21.2–26.2%), cattle (19.3%, 16.4–22.5%), healthy individuals (6.2%, 5.4–7.1%), and patients (0.3%, 0.0–1.1%). Soil and freshwater samples all tested negative for tet(X). A total of 289 TPB were isolated from 7516 samples (120/1181 chicken, 82/669 cattle, 68/3229 healthy individual, 17/239 freshwater fish and 2/2121 clinical samples). TPB distributed in six major families of bacteria including Moraxellaceae (n = 99, 34.3%), Flavobacteriaceae (n = 95, 32.9%), Enterobacteriaceae (n = 83, 28.7%), Pseudomonadaceae (n = 9, 3.1%), Sphingobacteriaceae (n = 2, 0.7%) and unclassified Gammaproteobacteria (n = 1, 0.3%). Diverse tet(X) genes including tet(X2), tet(X3), tet(X4), tet(X5) and tet(X6) were identified from different TPB. The tet(X)-positive bacteria were highly diverse, with ST10 complex belonging to the dominant E. coli clone. Novel hosts of tet(X) including Enterobacter hormaechei, Ignatzschineria indica and Oblitimonas alkaliphila were identified. Isolates from different families exhibited different antimicrobial resistance profiles. Co-existence of tet(X) with other resistance genes such as floR (66.8%) and carbapenemase genes (33.2%) was commonly observed. tet(X) could be transferred among E. coli isolates at frequencies from 10−4 to 10−10. Species other than E. coli failed to transfer tet(X) gene to the E. coli recipient via conjugation. Discriminant analysis of principal components analysis suggested inter-host transmission of tet(X)-positive E. coli among diverse hosts was not observed. Future studies are needed to monitor the transmission trend as well as the impact of this resistance gene in clinical infection control.

Objectives: Intra-articular application of platelet-rich plasma (PRP) are found to effectively improve knee function in patients with Knee osteoarthritis (KOA). This study is to identify the factors that influence the effect of PRP in the treatment of KOA. Methods: PRP was performed with a rich-leukocyte autologous conditioned plasma (ACP) system in 82 patients who were diagnosed with KOA. A Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to score the level of KOA by 3 features as the evaluation indicator of therapeutic effect. Visual Analogue Scale (VAS), X-ray and subsequent Kellgren-Lawrence (K-L) scale level evaluation were performed before the treatment. Basic information of participants and disease duration were also collected. Simple correlation analysis, single-factor ANOVA and multivariant regression analysis were used for identifying factors associated with the efficiency of PRP injection. Results: WOMAC decreased after PRP therapy by 10.12 ± 0.98 points (P < 0.001). Simple correlation analysis and ANOVA suggest BMI, pre-treatment VAS scores, and pre-treatment K-L scale level positively correlated with the therapeutic effect of PRP treatment (P < 0.05), while the other factors were not significantly correlated with the effect (P > 0.05). Further multivariate model indicates that the responsible variable Y (Post-treatment changes of WOMAC scores) was affected by exploratory variables BMI (X1), VAS (X2), K-L scale level (X3) and Gender (X4) (F = 7.857, P < 0.001). The exploratory variable X3 had the biggest effect on Y.Conclusion: This study found that the therapeutic effect of PRP is better in male patients with higher BMI, higher VAS and lower K-L scale level.This study was qualified and registered in the Chinese Clinical Trial Registry as ChiCTR2000039856.

Background: Hyperuricemia (HUA) has become the most common and serious public health problem worldwide. In China, the prevalence of HUA in the Pearl River Delta (PRD) region of Guangdong Province has not been extensively investigated. Therefore, this study investigated the prevalence of HUA and its related factors among people aged 20–99 years in nine cities in the PRD.Methods: We selected 6491 health check participants from 9 cities in the PRD and collected participants’ anthropometric and biochemical test results for a cross-sectional study. We included 6491 participants and assessed their blood pressure (BP), body mass index (BMI), total cholesterol (TC), triglycerides (TG), glucose (Glu) and serum uric acid (UA) to analyze the regional prevalence of HUA and its related factors. HUA was indicated when fasting serum UA level was > 420 μmol/L in men and > 360 μmol/L in women.Results: Overall prevalence of HUA in our cohort was 34.05%; prevalence was higher in men than in women (41.53% vs 26.14%, P < 0.000). Characteristics associated with HUA were hypertension (odds ratio (OR), 5.506; 95% confidence interval (CI), 4.402–6.889), higher body mass index (BMI; OR: 1.746; 95% CI: 1.560–1.954), age 31–40 years (OR: 0.829; 95% CI: 0.706–0.973), age 61–70 years (OR: 1.434; 95% CI: 1.194–1.722) and age > 71 years (OR: 1.742; 95% CI: 1.397–2.173). In all subjects, serum UA was positively correlated with Glu, TG and TC. After we adjusted for age, BMI and BP, multivariate logistic-regression analysis showed that HUA risk factors were high TC (OR: 1.770; 95% CI: 1.459–2.147) and TG (OR: 1.961; 95% CI: 1.632–2.357) in men; and high Glu (OR: 1.508; 95% CI: 1.084–2.099), TC (OR: 1.341; 95% CI: 1.084–1.660) and TG (OR: 1.680; 95% CI: 1.290–2.187) in women.Conclusion: The prevalence of HUA was relatively high in the PRD of Guangdong Province. Relevant governmental bodies should focus on early diagnosis, early treatment and early intervention.

Objectives This study aimed to analyze the factors influencing sarcopenia in patients on maintenance hemodialysis (MHD) in Mainland China and explore the role of phase angle (PhA) in sarcopenia. Methods & Procedures We enrolled 346 patients on MHD with regular dialysis and collected relevant data. According to the diagnostic criteria of Asian sarcopenia working group, the patients were divided into sarcopenia and nonsarcopenia groups. The differences between groups were compared and the statistically significant factors were included in binary logistic regression analysis to screen for independent factors influencing sarcopenia. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the predictive value of PhA in sarcopenia. Results The prevalence of sarcopenia was 32.66% in patients on MHD. Logistic regression analysis showed that sarcopenia was significantly associated with age (odds ratio [OR] = 1.12; 95% confidence interval [95%CI]: 1.08–1.15; P Conclusion Our study showed that PhA was an important influencing factor of sarcopenia adjusted by age and BMI in Asian patients on MHD. PhA may have an optimistic predictive value to identify sarcopenia in these population, and it is convenient and accessible in clinical practice than the diagnostic criteria of sarcopenia.

This communication reports a viable low temperature method for scalable production of SnS2 nanomaterials with promising applications in visible-light photocatalysis and photovoltaics. SnS2 nanoflakes were synthesized via heating the mixture of NH4Cl, S and Sn powders in air at 250 °C for 2 h, followed by a washing process. X-ray diffraction, scanning electron microscope, and nitrogen adsorption–desorption isotherms characterization indicated the formation of pure SnS2 nanoflakes with a specific surface area of 32.081 m2/g. Comparative synthesis experiments manifested that NH4Cl played an indispensable role in our low temperature synthesis of SnS2. UV–vis absorbance spectrum demonstrated that the as-synthesized SnS2 nanoflakes had much higher absorption of visible-light than hydrothermally synthesized SnS2 and thermally exfoliated g-C3N4. Transient photocurrent measurements and photocatalytic tests indicated that our product had not only exceptionally larger photocurrent, but also significantly higher photocatalytic activity than hydrothermally synthesized SnS2 and thermally exfoliated g-C3N4 in the reduction of Cr(VI) under visible-light (λ > 420 nm) irradiation.

The solubility of 4-bromopyrazole in binary (methanol + water) and (ethanol + water) solvent mixtures were investigated by using the isothermal dissolution equilibrium method under atmosphere pressure. The maximum solubility was observed in neat methanol or ethanol. At the same mass fraction of methanol or ethanol and temperature, the solubility of 4-bromopyrazole was greater in (ethanol + water) than in (methanol + water) mixed solvents. The obtained solubility data were correlated with Jouyban-Acree model, modified Apelblat-Jouyban-Acree model and van’t Hoff-Jouyban-Acree model. The largest values of relative average deviation and the root-mean-square deviation were 3.59 × 10−2 and 6.60 × 10−3, respectively. Positive apparent enthalpies showed that dissolution of 4-bromopyrazole in these mixed solvents was an endothermic process. Preferential solvation parameters of 4-bromopyrazole were also derived by means of the inverse Kirkwood-Buff integrals method. The preferential solvation parameter was negative in water-rich mixtures but positive in intermediate composition and alcohol-rich mixtures. In the latter case, it is conjecturable that 4-bromopyrazole is acting as a Lewis acid with alcohol molecules. The co-solvent action may be related to the breaking of the ordered structure of water around the polar moieties of 4-bromopyrazole which increases the solvation of this solute. The solubility data and thermodynamic study expanded the physicochemical information about 4-bromopyrazole in binary solvent mixtures.

The formation and evolution of permafrost in China during the last 20 ka were reconstructed on the basis of large amount of paleo-permafrost remains and paleo-periglacial evidence, as well as paleo-glacial landforms, paleo-flora and paleofauna records. The results indicate that, during the local Last Glacial Maximum (LLGM) or local Last Permafrost Maximum (LLPMax), the extent of permafrost of China reached 5.3 ´ 106−5.4 ´ 106 km2, or thrice that of today, but permafrost shrank to only 0.80 ´ 106 −0.85 ´ 106 km2, or 50% that of present, during the local Holocene Megathermal Period (LHMP), or the local Last Permafrost Minimum (LLPMin). On the basis of the dating of periglacial remains and their distributive features, the extent of permafrost in China was delineated for the two periods of LLGM (LLPMax) and LHMP (LLPMin), and the evolution of permafrost in China was divided into seven periods as follows: (1) LLGM in Late Pleistocene (ca. 20000 to 13000−10800 a BP) with extensive evidence for the presence of intensive ice-wedge expansion for outlining its LLPMax extent; (2) A period of dramatically changing climate during the early Holocene (10800 to 8500−7000 a BP) when permafrost remained relatively stable but with a general trend of shrinking areal extent; (3) The LHMP in the Mid-Holocene (8500−7000 to 4000−3000 a BP) when permafrost degraded intensively and extensively, and shrank to the LLPMin; (4) Neoglaciation during the late Holocene (4000−3000 to 1000 a BP, when permafrost again expanded; (5) Medieval Warming Period (MWP) in the late Holocene (1000−500 a BP) when permafrost was in a relative decline; (6) Little Ice Age (LIA) in the late Holocene (500−100 a BP), when permafrost relatively expanded, and; (7) Recent warming (during the 20th century), when permafrost continuously degraded and still is degrading. The paleo-climate, geography and paleopermafrost extents and other features were reconstructed for each of these seven periods.

This letter reports for the first time on the photocatalysis of SnS2 nanotubes, with the goal of maximizing the potential of SnS2 for photocatalytic applications. SnS2 nanotubes were synthesized by a solvothermal method with the assistance of cobalt-nitrilotriacetic acid complex nanorods as the sacrificial template. The X-ray diffraction, Raman and X-ray photoelectron spectroscopy analyses indicated the formation of pure hexagonal phase SnS2. Scanning electron microscope and transmission electron microscope images revealed that the as-synthesized SnS2 comprised porous nanotubes, which were assembled from intertwined, 5 nm-thick nanosheets. Nitrogen adsorption-desorption isotherms disclosed that the as-synthesized SnS2 nanotubes had a much big specific surface area (232.8 m2/g). Photocatalytic experiments showed that the as-synthesized SnS2 nanotubes not only far surpassed SnS2 nanoflowers, nanoflakes and nanoparticles in the adsorption and visible-light-driven photocatalytic reduction of aqueous Cr(VI), but also had good recyclability. This study tells that the photocatalytic activity of SnS2 can be enhanced by the preparation of porous nanotubular microstructre.

The China–Russia Crude Oil Pipeline (CRCOP), 813 mm in diameter, is designed to transport 603,000 barrels of Siberian crude oil per day across 1030 km of frozen-ground. About 500 boreholes, with depths of 5 to 20 m, were drilled and cored for analyses, and the frozen-ground conditions were evaluated. After detailed surveys and analyses of the permafrost conditions along the pipeline route, a conventional burial construction mode at a nominal depth of 1.5 m was adopted. This paper discusses the principles and criteria for the zonation and assessment of the frozen-ground environments and conditions of engineering geology for the design, construction, and operation of the pipeline system based on an extensive and in-depth summary and analysis of the survey and exploration data. The characteristics of pipelining crude oil at ambient temperatures in the permafrost regions and the interactive processes between the pipeline and foundation soils were taken into account. Two zones of frozen-ground environment and conditions of engineering geology, i.e., seasonally-frozen-ground and permafrost, were defined on the basis of the regional distribution and differentiations in frozen-ground environments and conditions. Then, four subzones of the permafrost zone were classified according to the areal extent, taking into consideration the temperatures and thicknesses of permafrost, as well as changes in vegetation coverage. In the four subzones, 151 sections of engineering geology were categorized according to the ice/moisture contents of the permafrost, as well as the classes of frost-heaving and thaw-settlement potentials. These 151 sections are comprehensively summarized into four types for engineering construction and operation: good, fair, poor, and very poor, for overall conditions of engineering geology. The zonation, assessment principles and criteria have been applied in the design of the pipeline. They have also been used as the scientific bases for the construction, environmental management, operation and maintenance/contingency plans.

The Qinghai–Tibet Highway and Railway (the Corridor) across the Qinghai–Tibet Plateau traverses 670 km of permafrost and seasonally frozen-ground in the interior of the Plateau, which is sensitive to climatic and anthropogenic environmental changes. The frozen-ground conditions for engineering geology along the Corridor is complicated by the variability in the near-surface lithology, and the mosaic presence of warm permafrost and talik in a periglacial environment. Differential settlement is the major frost-effect problem encountered over permafrost areas. The traditional classification of frozen ground based on the areal distribution of permafrost is too generalized for engineering purposes and a more refined classification is necessary for engineering design and construction. A proposed classification of 51 zones, sub-zones, and sections of frozen ground has been widely adopted for the design and construction of foundations in the portion of the Corridor studied. The mean annual ground temperature (MAGT), near-surface soil types and moisture content, and active faults and topography are most commonly the primary controlling factors in this classification. However, other factors, such as local microreliefs, drainage conditions, and snow and vegetation covers also exert important influences on the features of frozen ground. About 60% of the total length of the Corridor studied possesses reasonably good frozen-ground conditions, which do not need special mitigative measures for frost hazards. However, other sections, such as warm and ice-rich or -saturated permafrost, particularly in the sections in wetlands, ground improvement measures such as elevated land bridges and passive or proactive cooling techniques need to be applied to ensure the long-term stability of thermally unstable, thick permafrost subsoils, and/or refill with non-frost-susceptible soils. Due to the long-history of the construction and management of the Corridor by various government departments, adverse impacts of construction and operation on the permafrost environment have been resulted. It is recommended that an integrated, executable plan for the routing of major construction projects within this transportation corridor be established and long-term monitoring networks installed for evaluating and mitigating the impact from anthropogenic and climatic changes in frozen-ground conditions.

The sensitive permafrost environments along the Qinghai–Tibet Engineering Corridor (QTEC) from Golmud to Lhasa are controlled by periglacial processes, geography, geocryology and the local climate. During the past 50 years, permafrost has been degrading at a rapid rate due to the combined influences of steadily increasing human activities and persistent climatic warming, and extensive accelerated degradation has been observed along the QTEC. In many locations, the surface vegetation and the top soils have been completely removed, or destroyed, and have led to significantly increased water and soil erosion, with extensive and serious environmental and engineering impacts. The vegetation along the QTEC is dominated by alpine grasslands and meadows. The alpine grasslands have a better capability for recovery from the damages than the meadows. At sections where the vegetation and soils were severely damaged, it will take 20–30 years for alpine grasslands to recover their ecological structures and biodiversity similar to that of the original conditions, whereas it will take 45–60 years for the alpine meadows. The environmental management and protection along the QTEC are urgent and important for the long-term stability of engineering foundations, and for the sustainable development on the Qinghai–Tibet Plateau (QTP). The proper protection and management requires the development of a non-interference plan and acceleration in the enactment and enforcement of environmental protection (laws, regulations and stipulations) based on an extensive and thorough understanding and practical rehabilitation techniques for disturbed or damaged permafrost environments.

Permafrost on the Qinghai-Tibet Plateau (QTP) is widespread, thin, and thermally unstable. Under a warming climate during the past few decades, it has been degrading extensively with generally rising ground temperatures, the deepening of the maximum summer thaw, and with lessening of the winter frost penetration. The permafrost has degraded downward, upward and laterally. Permafrost has thinned or, in some areas, has totally disappeared. The modes of permafrost degradation have great significance in geocryology, in cold regions engineering and in cold regions environmental management. Permafrost in the interior of the QTP is well represented along the Qinghai-Tibet Highway (QTH), which crosses the Plateau through north to south and traverses 560 km of permafrost-impacted ground. Horizontally, the degradation of permafrost occurs more visibly in the sporadic permafrost zone in the vicinity of the lower limit of permafrost (LLP), along the margins of taliks, and around permafrost islands. Downward degradation develops when the maximum depth of seasonal thaw exceeds the maximum depth of seasonal frost, and it generally results in the formation of a layered talik disconnecting the permafrost from the seasonal frost layer. The downward degradation is divided into four stages: 1) initial degradation, 2) accelerated degradation, 3) layered talik and 4) finally the conversion of permafrost to seasonally frozen ground (SFG). The upward degradation occurs when the geothermal gradient in permafrost drops to less than the geothermal gradients in the underlying thawed soil layers. Three types of permafrost temperature curves (stable, degrading, and phase-changing transitory permafrost) illustrate these modes. Although strong differentiations in local conditions and permafrost types exist, the various combinations of the three degradation modes will ultimately transform permafrost into SFG. Along the QTH, the downward degradation has been proceeding at annual rates of 6 to 25 cm, upward degradation at 12 to 30 cm, and lateral degradation in the sporadic permafrost zone at 62 to 94 cm during the last quarter century. These rates exceed the 4 cm per year for the past 20 years reported for the discontinuous permafrost zone in subarctic Alaska, the 3 to 7 cm per year reported in Mongolia, and that of the thaw-stable permafrost in subarctic Yakutia and Arctic Alaska.

Desertification in Qinghai-Xizang (Tibet) Plateau is part of Chinese desertification. In the past decades, due to the climate warming, the climate condition in Qinghai-Xizang (Tibet) Plateau has been relatively dry. This has resulted in permafrost degradation and other environmental problems. In addition, the vegetation and the soil layer were also destroyed by unreasonable economic activities. Cultivated and grassland lands have become deserted. Nowadays, the desertification is still expending. In this paper, the factors affecting the desertification in Qinghai-Xizang (Tibet) Plateau were examined, and the desertification as well as its relationship with permafrost degradation was also discussed.

For thoroughly understanding the roadbed failure at permafrost section of Qinghai–Tibet Highway (QTH), the radiation and thermal balance on the surface of asphalt layer of roadbed and nearby natural ground in two different types of permafrost sections were observed in two study sites located at Kunlun Mountains Pass and No. 66 Road Maintenance Station. The thermal balance on the two different surface and annual thermal rotation of the roadbed were calculated based on the data observed. It was concluded that the changes of thermal regime were the basic causes responsible for the roadbed subsidence and the formation of thawed zone. The formation and evolution processes of thawed zone in roadbed and their stability were discussed. At the end of the paper, the would-be maximum depth of the artificial permafrost table and its evaluation time as well as the final stable thickness of thawed zone below the roadbed were calculated. Based on the work, feasible measures to rehabilitate the QTH were put forward.

The interaction between permafrost and atmosphere is accomplished through transfer of heat and moisture in the overlay active layer. Thus, the research on the thermal and hydrodynamics of active layer during the thawing and freezing processes was considered a key to revealing the heat and moisture exchanges between permafrost and atmosphere. The monitoring and research on active layer were conducted because permafrost occupies about two thirds of the total area of the Tibetan Plateau. Based on the analysis of the ground temperature data and soil moisture data of monitoring near the Wudaoliang region of the Tibetan Plateau, the thawing and freezing processes of active layer were divided into four stages, i.e. summer thawing stage (ST), autumn freezing stage (AF), winter cooling stage (WC) and spring warming stage (SW). Coupled heat and water flow is much more complicated in ST and AF, and more amount of water is migrating in these two stages. Heat is transferred mainly via conductive heat flow in the other two stages, and less water migrated. Four water migration and coupled heat flow processes were addressed for the thawing and freezing stages, which are water infiltration driven by gravity, moisture advection and distillation driven by temperature and osmotic gradients, water migration driven by capillarity and unfrozen water migration driven by temperature gradient. The water content near the permafrost table tends to increase after one thawing and freezing cycle, which is the main reason for the development of thick ground ice layer near permafrost table.

Monitoring of frozen soil hydrology in macro-scale was performed by Chinese and Japanese scientists from 1997 to 1998. Quality measured data were obtained. Measured data on soil moisture and temperature are preliminarily analyzed. Based on profiles of soil temperature and moisture in individual measured sites, intra-annual freezing and melting process of soil is discussed. Maximum frozen and thawed depths and frozen days in various depths are estimated. The work emphasized the spatial distribution on soil temperature and moisture in macro-scale and the effect of topography on conditions of soil water and heat.

The objective of this study is to develop an algorithm for mapping soil moisture by using the spatial and temporal distributions of the microwave backscattering coefficients of the ground surface. The scattering model that includes Integral Equation Method (IEM) are applied to the two images of L-band Synthetic Aperture Radar (SAR) mounted on JERS-1 taken over the Tibetan Plateau in January and August, 1993. The backscattering coefficient of the ground surface is affected not only by soil moisture but also by the other factors such as surface roughness, vegetation and soil composition. To obtain the values related to roughness, the ground-based measurements are carried out “GAMETibet POP” in summer, 1997. Two experimental areas with different surface characteristics were selected. The soil moisture map in August was derived from the scattering model with the relationship between two surface roughness parameters inputted. The distribution of the calculated soil moisture on the Tibetan Plateau corresponds to the result of the field inspection.

In this paper, performance of CO 2 Emission (CE) and Investment Value (IV) of a Wooden Detached House shape were studied for bi-objective optimization. Sapporo, Tokyo and Naha as Japanese three typical locations were considered. Feasible solutions of optimal Pareto curve illustrated that: shape with larger southern roof area and fully covered with PVS perform the best in IV than others, and pitche of roof in the given locations should be less than its ideal solar absorption case. To minimize CE, roof with larger pitch is needed.

The 4.45 m-thick pure ice lens have been discovered firstly at depth from 19.81–24.26 m in the bore No.6, which locates in north bank of the Ngoring Lake. In source region of the Huanghe (Yellow) River,14C dating, X-ray diffraction, pollen analysis, micropalaeontology, chemical components, environmental isotope2H,3H,18O and freezing point of the ice and water samples from the bore have been tested and microorganism in the ice have been also appraised with microscope. Combined with the research on geomorphy and Quaternary around the lake, the ice lens are determined as a kind of deep-buried lake ice, formed in 35,030–45,209 yr.B.P., and annual mean air temperature was about −10°C during that time.

In receiver diversity systems, signal replicas will suffer from channel correlations if there are insufficient spacings for component receivers. Knowledge of the channel correlation is important for system performance assessment and improvement. In this paper, we give a theoretical study of the channel correlation in receiver diversity systems. Based on the plane-wave model and the extended Rytov theory for the ABCD ray-matrix formulation, expressions for the channel correlation are derived under general atmospheric conditions. The effects of antenna spacing, turbulence strength, receiver aperture size, and wavelength are examined in detail and the corresponding physical mechanisms for the results are discussed. An approximation for estimating the channel correlation length under strong turbulence conditions is obtained.

The Source Area of the Yellow River is located in the mosaic transition zones of seasonally frozen ground, and discontinuous and continuous permafrost on the northeastern Qinghai–Tibet Plateau. Vertically, permafrost is attached or detached from frost action. The latter can be further divided into shallow (depth to the permafrost table ≤8 m), deep (>8 m) and two-layer permafrost. Since the 1980s, air temperatures have been rising at an average rate of 0.02 °C yr−1. Human activities have also increased remarkably, resulting in a regional degradation of permafrost. The lower limit of permafrost has risen by 50–80 m. The average maximum depth of frost penetration has decreased by 0.1–0.2 m. The temperatures of the suprapermafrost water have increased by 0.5–0.7 °C. General trends of permafrost degradation include reduction in areal extent from continuous and discontinuous to sporadic and patchy permafrost, thinning of permafrost, and expansion of taliks. Isolated patches of permafrost have either been significantly reduced in areal extent, or changed into seasonally frozen ground. Degradation of permafrost has led to a lowering of ground water levels, shrinking lakes and wetlands, and noticeable change of grassland ecosystems alpine meadows to steppes. The degradation of alpine grasslands will cause further degradation of permafrost and result in the deterioration of ecological environments as manifested by expanding desertification and enhancing soil erosion.