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Abstract To address the problems of wall collapse, cuttings slurrying, and scaling on the inner wall of the drill pipe, which often occur in small-diameter diamond wireline core drilling, the inhibition properties of polyvinyl alcohol (PVA) was investigated, and the formulation of solids-free drilling fluid with PVA as the inhibitor were completed. PVA has the advantages of fast adsorption and easy regulation of rheological properties Firstly the inhibition effect of PVA was compared with that of common inorganic salts (sodium chloride, NaCl, potassium chloride, KCl) by bentonite dispersion test, linear swelling test, shale rolling recovery test and mud ball immersion test in this study. Then, the inhibition mechanism of PVA was analyzed with potentiometric particle size tests, Fourier transform infrared (FT-IR) and X-ray Diffraction (XRD) measurements. Based on the outstanding inhibition performance of PVA, tackifiers and filtration reducers were preferred through the compatibility test. And finally, the effects of various contaminants on the comprehensive performance of the formulated solids-free drilling fluids were evaluated. The results showed that PVA exhibited better inhibition of clay hydration and dispersion in shale recovery and linear swelling compared to NaCl and KCl, which was particularly evident in the mud ball immersion test. FT-IR and XRD tests revealed that the inorganic salts were used to replace the cations with larger radius and high degree of hydration in the clay layer by ion exchange ti achieve the effect of clay de-watering by reducing the spacing of the clay interlayer and the electrostatic repulsion between the particles. However, PVA is strongly adsorbed on the clay surface in the form of hydrogen bonds due to its unique multi-hydroxyl chain structure, forming a hydrophobic barrier to prevent water molecules from entering the clay layer, thus inhibiting the hydration and swelling of the clay. Using PVA as an inhibitor, compounded with xanthan gum, sulfonated lignite resin and sulfonated gilsonite (FT-1), the solids-free drilling fluid is promising for use in diamond wireline core drilling in complex formations.

Abstract Background Tianjin is one of the cities with the highest prevalence of hypertension in China and one of the first regions to develop community management of hypertension. Our aim was to analyze the characteristics of hypertension in the last 16 years, and estimate the population attributable fraction for cardiovascular mortality in Tianjin, China. Methods We compared the epidemiological characteristics of hypertension between 2002 and 2018 by analyzing data from the National Nutrition and Chronic Disease Risk Factor Survey. Subsequently, we obtained the cause-specific mortality in the same year from the Tianjin All Cause of Death Registration System (CDRS), and the population attributable fraction was used to estimate the annual cardiovascular disease (CVD) deaths caused by hypertension. Results In 2002 and 2018, the crude prevalence, awareness, treatment rate in diagnosed, control rate in treated, and overall control rate of hypertension were 36.6% and 39.8%, 36.0% and 51.9%, 76.0% and 90.1%, 17.4% and 38.3%, 4.8% and 17.9%, respectively (P

Introduction This study aims to estimate the impact of smoking-attributable mortality of selected cancers, in the period 2010–2019 in Tianjin, China. Methods A case-control study was conducted to assess the smoking-attributed major causes of cancer deaths. Unmatched multiple logistic regression was used to calculate mortality risk ratios. Results Smoking-attributable cancer deaths were 23709 (28.87%) among adult males and 8648 (13.37%) among adult females in the period 2010–2019 in Tianjin, China. Lung cancer remains the largest cause of smoking-attributable deaths; among men, the death rates were 49.06% of lung cancers, 27.55% of mouth, pharynx, larynx, or esophagus cancers, 13.56% of kidney and other urinary cancers, and 10.11% of liver cancers; among women the corresponding death rates were 31.56% of lung cancers and 10.59% of the mouth, pharynx, larynx, or esophagus cancer, 10.56% of bladder cancers. Smoking-attributed cancer deaths in men increased from 1817 in 2010 to 2695 in 2019; for women, the number remained stable at just over 800 per year during the past decade. Conclusions At least one in three cancer deaths in men and one in six in women would be potentially preventable through appropriate control of tobacco smoking in Tianjin, China. Effective control programs against tobacco smoking should be further implemented.

Abstract Background Pulmonary sequestration (PS) is a rare lesion with independent blood supply from an anomalous systemic artery. A timely resection is considered as the best treatment for PS. Three-dimensional computed tomography angiography (3D-CTA) has been widely utilized for precise thoracic surgery. This study aimed to investigate the role of preoperative 3D-CTA and resection simulation in uniportal video-assisted thoracoscopic surgery (VATS) anatomical lung surgery for PS. Methods The data of 20 consecutive PS patents undergoing anatomic lung resection between April 2011 and May 2021 in a single centre were retrospectively reviewed. These patients were divided into the 3D-CTA group (10 patients) and the control group (10 patients) according to the initial surgical planning with or without 3D-CTA. The perioperative parameters regarding safety and fluency such as the incidence of conversion to open thoracotomy, operation time, blood loss, complications and chest tube duration were analyzed. Results This cohort included 12 female and 8 male patients, with a mean age of 45 years old (range 24–60 years). Nine cases demonstrated recurrent febrile, cough, or hemoptysis; whereas the other 11 patients were asymptomatic on admission. Eighteen (90.0%) intralobar and 2 extralobar PS were confirmed, whereas 18 (90.0%) lesions were located in the left thorax. The feeding vessels originated from the thoracic aorta in 16 patients (80.0%), the abdominal aorta in 3 (15.0%), and the inferior phrenic artery in 1 patient (5.0%). There was no major bleeding or 30 days mortality. The initial surgical planning included 9 uniportal and 1 two-port VATS in the 3D-CTA group, as compared with 10 two-port VATS in the control group. Thirteen lobectomies, 5 segmentectomies and 2 mass excisions were performed. However, no conversion was needed in the 3D-CTA group; whereas 6 (60.0%) conversions (4 to multiple-port and 2 to thoracotomy) occurred in the control group, indicating a significant difference (P = 0.003). In addition, the operation time in the 3D-CTA group was significantly shorter than those in the control group [(108.5 ± 24.9) min vs. (154.5 ± 39.4) min, P = 0.006]. The other surgery-related outcomes were similar between the two groups. Conclusion Preoperative 3D-CTA facilitates the safe and fluent performance of uniportal VATS anatomical lung resection for PS with shortened operation time and lessened surgical conversions.

Abstract Objective Compare the urban-rural disparity in cancer mortality and changing trend during the past 18 years in Tianjin, China. Methods Cancer death data were obtained from Tianjin All Cause of Death Registration System (CDRS), which covers the whole population of Tianjin. We calculated and compared the constituent ratio of cancer deaths, age-standardized mortality rate(ASR)and changing trends between urban and rural areas. Results From 1999 to 2016, a total of 245,744 cancer deaths were reported, accounting 21.7% of all deaths in Tianjin. The ASR of total cancer mortality was higher in urban areas than in rural areas. A total of 33,739 persons were avoided dying of cancers in rural area compared to the urban death level from 1999 to 2016, which was 40.1% compare to the current level of rural areas. But the gap between urban and rural areas became narrowed gradually. The urban-rural ratios (urban/rural) of total cancer mortality changed from 1.76 (125.7/71.5)[95%CI,1.67,1.84] in 1999 to 1.11 (99.6/90.0)[95%CI,1.06,1.15] in 2016. The ASR of lung, liver and esophagus cancer became higher in rural areas than in urban areas in 2016. Conclusion Cancer transition was obviously occurred in Tianjin and showed different speeds and big gap between urban and rural areas. Much more attention was needed to pay in rural areas which still have increasing trends in most cancers mortality recently.

Abstract Glioma is one of the primary malignant brain tumours in adults, with a poor prognosis. Pharmacological reagents targeting glioma are limited to achieve the desired therapeutic effect due to the presence of blood‐brain barrier (BBB). Effectively crossing the BBB and specifically targeting to the brain tumour are the major challenge for the glioma treatments. Here, we demonstrate that the well‐defined small extracellular vesicles (sEVs) with dual‐targeting drug delivery and cell‐penetrating functions, modified by Angiopep‐2 and trans‐activator of transcription peptides, enable efficient and specific chemotherapy for glioma. The high efficiency of engineered sEVs in targeting BBB and glioma was assessed in both monolayer culture cells and BBB model in vitro, respectively. The observed high targeting efficiency was re‐validated in subcutaneous tumour and orthotopic glioma mice models. After loading the doxorubicin into dual‐modified functional sEVs, this specific dual‐targeting delivery system could cross the BBB, reach the glioma, and penetrate the tumour. Such a mode of drug delivery significantly improved more than 2‐fold survival time of glioma mice with very few side effects. In conclusion, utilization of the dual‐modified sEVs represents a unique and efficient strategy for drug delivery, holding great promise for the treatments of central nervous system diseases.

Small target detection has been widely used in applications that are relevant to everyday life and have many real-time requirements, such as road patrols and security surveillance. Although object detection methods based on deep learning have achieved great success in recent years, they are not effective in small target detection. In order to solve the problem of low recognition rate caused by factors such as low resolution of UAV viewpoint images and little valid information, this paper proposes an improved algorithm based on the YOLOv5s model, called YOLOv5s-pp. First, to better suppress interference from complex backgrounds and negative samples in images, we add a CA attention module, which can better focus on task-specific important channels while weakening the influence of irrelevant channels. Secondly, we improve the forward propagation and generalisation of the network using the Meta-ACON activation function, which adaptively learns to adjust the degree of linearity or nonlinearity of the activation function based on the input data. Again, the SPD Conv module is incorporated into the network model to address the problems of reduced learning efficiency and loss of fine-grained information due to cross-layer convolution in the model. Finally, the detection head is improved by using smaller, smaller-target detection heads to reduce missed detections. We evaluated the algorithm on the VisDrone2019-DET and UAVDT datasets and compared it with other state-of-the-art algorithms. Compared to YOLOv5s, mAP@.5 improved by 7.4% and 6.5% on the VisDrone2019-DET and UAVDT datasets, respectively, and compared to YOLOv8s, mAP@.5 improved by 0.8% and 2.1%, respectively. For improving the performance of the UAV-side small target detection algorithm, it will help to enhance the reliability and safety of UAVs in critical missions such as military reconnaissance, road patrol and security surveillance.

To deal with the problems of wellbore collapse, mud making and mud lining in drilling strings, a solid-free anti-collapse drilling fluid with polyvinyl alcohol as inhibitor was developed. The inhibition effect of commonly used inhibitors was studied by shale hot rolling recovery test, critical addition of bentonite test, and mud boulder soaking test. The types and dosage of viscosifiers and water loss reducers were determined by compatibility test, and the influence of different pollutants on the comprehensive properties of the formulated drilling fluid were compared. Experimental results showed that compared with the conventional inorganic salt such as NaCl and KCl, polyvinyl alcohol had a stronger inhibition effect which was positively correlated with polymerization degree. XC, SPNH and FT-1 could be used as viscosifier and water loss reducers to prepare the drilling fluid, respectively. The performance of formula drilling fluid under the pollution of 35%NaCl, 4% CaCl2 and 12% calcium bentonite can be stable in the temperature of 110 ℃, indicating that the prepared drilling fluid can be used in the strong mud making strata, fractured strata, salt bed and other complex strata in the depth of 3 000 m.

Abstract A growing number of circular RNAs (circRNAs) have been identified and verified in several cancers. However, highly efficient therapeutic methods based on circRNAs in lung cancer remain largely unexplored. In the present study, we identified a novel circular RNA, hsa_circ_103820, based on Gene Expression Omnibus (GEO) data. Functionally, overexpression of hsa_circ_103820 showed significant inhibitory effects on the proliferation, migration and invasion of lung cancer cells, and knockdown of hsa_circ_103820 played promoting roles. Regarding the mechanism, we revealed that miR-200b-3p was a direct target of hsa_circ_103820 and that LATS2 and SOCS6 were the downstream target genes of miR-200b-3p. Therefore, we identified a novel potential tumor suppressive function of hsa_circ_103820 in lung cancer.

We demonstrate a triple-wavelength thulium-doped fiber random laser using a 10 cm long random fiber grating to provide random distributed feedback and a superimposed fiber Bragg grating as the wavelength-selective mirror. The random fiber grating inscribed in single-mode fibers using a femtosecond laser provides strong random distributed feedback that avoids the use of long distance fibers and leads to a relatively low threshold power. Triple-wavelength random laser output at wavelengths of 1943.6, 1945.0 and 1946.3 nm was achieved with a relatively low threshold power of 2.01 W, a slope efficiency of 7.86% and a maximum output power of 151.8 mW when it was pumped using a 793 nm laser diode. The 3 dB linewidth was less than 0.1 nm and the optical signal-to-noise ratio was up to 45.6 dB. Good wavelength stability was achieved, which was attributed to the narrow band and stable reflection of the superimposed fiber Bragg grating. The time-domain characteristics of the laser output were also measured and analyzed, and some random self-pulsing caused by relaxation oscillations were observed.

Polymer has a significant effect on the high temperature rheology of drilling fluid.The effects of polymer type, addition amount, shear time, salt and clay on the HTHP rheological properties were compared and analyzed, and the relationship of shear rate and shear stress was fitted to different rheological models.The increase of temperature, shear time and salt amount all led to the decrease of viscosity, especially when the temperature exceeded 190℃.In the cooling progress, the viscosity recovery rates of polymer solutions containing 5% HCOONa and 5% NaCl are 86.8% and 2.7%, respectively.Bingham model was used to characterize the mixture of polymer and clays, and the maximum yield point was 5.47 Pa at 220℃.Heating increases the tendency of the polymer solution to change from pseudoplastic to Newtonian.Above 130℃, the tendency of viscosity to decrease is obvious duedue to shear time.Meanwhile, the viscosity of the formate-containing polymer salt solution is higher than that of the chlorinated salt, and the viscosity retention rate of the former in the cooling process is also higher.The presence of clay enhances the structure force of the polymer solution, which is helpful for cuttings transportation at high temperatures.

Many reports have shown that patients with Hp-associated chronic gastritis exhibit anxiety and poor sleep quality. However, less is known about the effects and specific manifestations of Hp-associated chronic gastritis on autonomous activity and sleep quality in animals. Here, we investigated the effect of Helicobacter pylori (Hp)-associated chronic gastritis on autonomous activity and sleep quality in mice. To do this, a Hp-associated chronic gastritis mouse model was first established, then analyzed for autonomous activity, relative to controls, for 15 min using an autonomous activity tester. Next, sleep quality of mice was detected by sodium pentobarbital-induced sleep experiment and results compared between groups. The results showed that male mice in the model group exhibited higher activity counts but lower forelimb lift counts, relative to those in the control group, although there were no significant differences (all p > .05). Conversely, female mice in the model group recorded lower activity counts, albeit at no significant difference (p > .05), and significantly lower counts of forelimb lift (p < .05), relative to those in the control group. Notably, male mice in the model group had longer sleep latency and shorter sleep duration than those in the control group, albeit at no significant differences (all p > .05). On the other hand, female mice in the model group recorded significantly longer sleep latency as well as shorter sleep duration compared to those in the control group (all p < .01). We conclude that Hp-associated chronic gastritis exerts certain effects on autonomous activity and sleep quality of mice in a gender-dependent manner. Notably, female mice with Hp-associated chronic gastritis had lower activity and forelimb lift counts, as well as prolonged sleep latency, and shortened sleep duration. These effects were all statistically significant except for activity counts.

Abstract Background The aim of this study was to examine the trends in the mortality rate and years of life lost (YLL) rate of lung cancer in Tianjin, China, during the period from 1999 to 2016. Methods Lung cancer death data were obtained from Tianjin residents' all‐cause death monitoring system, which covers the whole population of Tianjin. Crude mortality rate, age‐standardized mortality rate, truncated rate (35–64 years), YLL and age‐standardized YLL rate data were calculated and trends examined. Results From 1999 to 2016, a total of 93 358 lung cancer deaths were reported in Tianjin, which accounted for 38.0% of all cancer deaths (93 358/245744). The crude mortality rate of lung cancer had increased 58.5% from 1999 (40.15/100000) to 2016 (63.64/100000), average annual percent change (AACP) = 2.9%, P

In order to realize the optimization of urban spatial patterns in the Yellow River Basin, a study on the inefficient use of urban land in the Yellow River Basin was carried out. In this study, Dali County and Hancheng County in Weinan City are selected as the research areas. Firstly, the analytic hierarchy process is used to build a comprehensive evaluation system for the identification of inefficient land in stock; secondly, the standard deviation ellipse method and spatial kernel density estimation method are used to quantitatively analyze the spatial distribution characteristics of inefficient land. Thirdly, the contribution model is used to analyze the influencing factors of inefficient land use. Finally, corresponding redevelopment suggestions are given for each type of inefficient land. The results show that Dali had the smallest area of inefficient land; second is Xincheng Street in Hancheng City; and Longmen Town, Hancheng City has the largest area. The distribution of inefficient land in Dali and Longmen Town in Hancheng City is relatively balanced, while the distribution of all kinds of inefficient land in Xincheng Street in Hancheng City is not concentrated. The density of the road network is the most important contributing factor to inefficient land use in the study area. This paper comprehensively uses the methods of economics and geography to study inefficient land use, quantifies the spatial-temporal characteristics and influencing factors of land use units, explores the spatial patterns of land use and enriches the research into relevant theories.

Abstract Nowadays, the application of polymer in petroleum industries due to its feasibility with enhancing hole cleaning, less formation damage characteristics of drilling fluids has been particularly advantageous in deep well operation. However, figuring out the influence mechanism of temperature on the rheological behavior of polymer fluids and keeping the excellent rheological regulation at high temperature and high pressure (HTHP) are still serious issues for the mud designers. In this work, the rheological properties of a commonly used drilling fluid polymer treating agent named Driscal-D were tested under HTHP conditions by Fann 50SL rheometer. The effects of polymer addition, electrolyte, clay type and antioxidant on the rheological properties of Driscal-D solution were studied in high-temperature environments. Results showed that the viscosity of the solutions tends to increase with the polymer addition increases, making its pseudoplastic characteristics more noticeable. As the temperature rises, the fluid loses viscosity, causing the polymer solution to evolve from pseudoplastic fluid to Newtonian fluid. The presence of the electrolyte and the oxygen scavenger leads to a decrease in the viscosity of the solution, but in high-temperature environments, the solution adding formate or antioxidant has a higher viscosity retention rate than the pure solution at low shear rates (

High temperature would dramatically worsen rheological behaviors and increase filtration loss volumes of drilling fluids. Synthetic polymers with high temperature stability have attracted more and more attention. In this paper, a novel quadripolymer was synthesized using 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylamide (AM), sodium styrene sulfonate (SSS), and dimethyl diallyl ammonium chloride (DMDAAC). Firstly, the molecular structure was studied by Fourier transform–infrared spectroscope (FT-IR) and nuclear magnetic resonance (1H-NMR) analysis. It was shown that the synthetic polymer contained all the designed functional groups. Moreover, the effect of temperature and the quadripolymer concentration on the rheological behavior and filtration loss of the bentonite-free drilling fluid were investigated. It was experimentally established that when the adding amount of the quadripolymer was 0.9 wt%, the prepared drilling fluid systems exhibited relatively stable viscosities, and the filtration losses could be controlled effectively after hot rolling aged within 180 °C. Further, it was confirmed that the bentonite-free drilling fluid containing the synthesized quadripolymer had good reservoir protection performance. In conclusion, the synthetic quadripolymer is a promising rheology modifier and a filtrate reducer for the development of the bentonite-free drilling fluid at high temperature.

Introduction The All Causes of Death Surveillance (ACDS) system was used to measure smoking-attributed mortality by inserting questions on smoking on death certificates. Smoking status information of the deceased has been routinely collected in death certificates since 2010. We describe a death registry-based casecontrol study using smoking and cause-of-death data for the period 2010–15. Methods From 2010, three questions about the smoking status of the deceased were inserted in a revised death certificate: 1) Smoking status (current smoker, quit smoking, never smoker); 2) Number of cigarettes per day smoked; and 3) Number of years of smoking. A data-accuracy survey of 1788 telephone interviews of the family of the deceased was also conducted. Smoking habits (current/ex-smoker vs non-smoker) were compared in study cases (persons who died of lung cancer and other diseases known to be caused by smoking) and the controls (never smokers). Multivariate logistic regression analysis was conducted to estimate relative risks, RR (odds ratios) for smoking-attributed mortality, for lung cancer and all causes of death related to smoking, adjusted for 5-year interval age groups, education, marital status, and year of death. Results During the study period (2010–15), the annual crude death reporting rates ranged from 6.5‰ to 7.0‰. The reporting rates of smoking status, smoking history and the number of cigarettes smoked daily were 95.5%, 98.6% and 98.6%, respectively. Compared to never smokers, the RR of ever smoking in males was 1.38 (95% CI: 1.33–1.43) for all causes of smoking-related deaths and 3.07 (95% CI: 2.91–3.24) for lung cancer, while in females the values were 1.46 (95% CI: 1.39–1.54) for all causes of smoking-related deaths and 4.07 (95% CI: 3.81–4.35) for lung cancer. The results in Tianjin are in accord with published results from previous studies. Conclusions Levels and trends in smoking attributed mortality can be measured at low cost by using the stable, complete and effective ACDS system in Tianjin.

The optimal delivery route problem for truck–drone delivery is defined as a traveling salesman problem with drone (TSP-D), which has been studied in a wide range of previous literature. However, most of the existing studies ignore truck waiting time at rendezvous points. To fill this gap, this paper builds a mixed integer nonlinear programming model subject to time constraints and route constraints, aiming to minimize the total delivery time. Since the TSP-D is non-deterministic polynomial-time hard (NP-hard), the proposed model is solved by the variable neighborhood tabu search algorithm, where the neighborhood structure is changed by point exchange and link exchange to expand the tabu search range. A delivery network with 1 warehouse and 23 customer points are employed as a case study to verify the effectiveness of the model and algorithm. The 23 customer points are visited by three truck–drones. The results indicate that truck–drone delivery can effectively reduce the total delivery time by 20.1% compared with traditional pure-truck delivery. Sensitivity analysis of different parameters shows that increasing the number of truck–drones can effectively save the total delivery time, but gradually reduce the marginal benefits. Only increasing either the truck speed or drone speed can reduce the total delivery time, but not to the greatest extent. Bilateral increase of truck speed and drone speed can minimize the delivery time. It can clearly be seen that the proposed method can effectively optimize the truck–drone delivery route and improve the delivery efficiency.

In order to study the relationship between carbon emission and economic growth in China’s transportation industry and the driving factors of carbon emission, the Logarithmic Mean Divisia Index (LMDI) decomposition model of carbon emission elastic decoupling and carbon emission driving factors is established. The results show that the carbon emission decoupling value of China’s transportation industry has obvious spatial disequilibrium characteristics, and the decoupling state of “weak decoupling-expansion negative decoupling- growth linkage” appears from coastal areas to inland are as a whole. From 2009 to 2016, there are five types of carbon emission Kuznets curves of China’s transportation industry, namely linear type, U type, inverted-U type, inverted-N type and wave type. The carbon emission intensity of transportation industry in many provinces still tends to increase with the increase of economy. The energy structure effect and the energy intensity effect have a relatively weak negative impact on the carbon emission in the transportation industry. However, the industry scale effect has a significant positive impact, which is the main factor to promote the growth of carbon emission.

Improving the logistics industry's green total factor productivity (LGTFP) is a key source of power to achieve its high-quality development (HQD) in China. Technological innovation (TI) and environmental regulation (ER) policies are vital factors that affect the improvement of LGTFP. Although the impact of ERs or TI on LGTFP has been extensively researched, few studies have examined their combined effect. This study utilizes panel data from 30 Chinese provinces during 2006-2020 to estimate LGTFP using the Epsilon-based measure and global Malmquist-Luenberger index. Moreover, this study employs a dynamic spatial Durbin model to explore the influence of TI on LGTFP and its spatial spillovers, as well as the modulatory effect of ER in the relations between TI and LGTFP. The results show that (1) China's LGTFP displays positive spatial spillovers and is influenced by the preceding period's level. (2) In the short term, an improvement in TI levels had a positive effect on local LGTFP, but negative spillovers on neighboring districts. Nevertheless, in the long run, an improvement in TI levels had a notably negative influence on local LGTFP but positive spillovers on adjacent regions. (3) ER had an "inverted U-shaped" modulatory roles with spatial spillovers on the relations between TI and LGTFP in the long-term. These discoveries offer valuable insights into the coordinated development of TI systems and ER policies, enabling the formation of a policy system that aligns with the logistics industry's HQD in China. [ABSTRACT FROM AUTHOR]

Objective. To examine and describe coronary heart disease (CHD) mortality and its pattern of change (trend) by sex, age, and area of residence (urban versus rural) in Tianjin, China, within the context of epidemiological transition, and compare it with current trends in the Americas and Europe. Methods. A total of 104 393 cases of CHD death in Tianjin occurring between 1999 and 2008 were monitored. Death due to CHD was coded using International Classification of Diseases (ICD) standards (ninth and tenth revisions). Standardized CHD mortality rates and their trends were analyzed by age, sex, and urban versus rural residence. Results. During the 10-year study period, the proportion of total deaths due to CHD in Tianjin increased significantly (from 16% to 24%) and age-standardized CHD mortality increased slightly (with no statistical differences), in contrast to CHD mortality trends in various countries in the Americas and Europe, which are declining. No difference was found in Tianjin's CHD mortality trend by sex. Overall CHD mortality was consistently higher among older age groups, males, and residents of urban areas. The proportion of CHD deaths occurring outside hospitals was 55.81%, with a declining trend over the study period. Rural areas had a higher proportion of outside-hospital CHD mortality than urban areas, but no difference was found across age groups. Conclusions. From 1999 to 2008, CHD mortality in Tianjin varied by sex, age, and urban versus rural area of residence. Future research to identify CHD risk factors and the populations most vulnerable to the disease is recommended to help strengthen CHD prevention. Strategies for CHD control similar to those used in various developed countries in the Americas and Europe should be developed to reduce the CHD burden in China. [ABSTRACT FROM AUTHOR]