Analysis of the causes of primary revision after unicompartmental knee arthroplasty: A case series

BACKGROUND Unicompartmental knee arthroplasty(UKA)has great advantages in the treatment of unicompartmental knee osteoarthritis,but its revision rate is higher than that of total knee arthroplasty.AIM To summarize and analyse the causes of revision after UKA.METHODS This is a retrospective case series study in which the reasons for the first revision after UKA are summarized.We analysed the clinical symptoms,medical histories,laboratory test results,imaging examination results and treatment processes of the patients who underwent revision and summarized the reasons for primary revision after UKA.RESULTS A total of 13 patients,including 3 males and 10 females,underwent revision surgery after UKA.The average age of the included patients was 67.62 years.The prosthesis was used for 3 d to 72 months.The main reasons for revision after UKA were improper suturing of the surgical opening(1 patient),osteophytes(2 patients),intra-articular loose bodies(2 patients),tibial prosthesis loosening(2 patients),rheumatoid arthritis(1 patient),gasket dislocation(3 patients),anterior cruciate ligament injury(1 patient),and medial collateral ligament injury with residual bone cement(1 patient).CONCLUSION The causes of primary revision after UKA were gasket dislocation,osteophytes,intra-articular loose bodies and tibial prosthesis loosening.Avoidance of these factors may greatly reduce the rate of revision after UKA,improve patient satisfaction and reduce medical burden.

Characteristics and Preliminary Causes of Tropical Cyclone Remote Precipitation over China

In this study,the characteristics and preliminary causes of tropical cyclone remote precipitation(TRP)over China during the period from 1979 to 2020 are investigated.Results indicated that approximately 72.42%of tropical cyclones(TCs)in the Western Pacific produce TRP over China.The peak months for TRP are July and August.The four key regions of TRP are the adjacent areas between the Sichuan and Shaanxi Provinces,the northern coast of the Bohai Sea,the coast of the Yellow Sea,and the southern coast area.The typical distance between the station with TRP and the TC center ranges from 1500 to 2500 km.Most of these stations are situated north to 60°west of north of the TC.The south–west water vapor transportation on the west side of the TC is crucial to TRP.TRP has a decreasing trend because of the decrease in the number of TCs that generate TRP.From the perspective of large-scale environmental conditions,a decrease in the integrated horizontal water vapor transport in China' Mainland,the weakening of upward motion at approximately 25°–35°N,which is inconducive to convection,and an increase in low-level vertical wind shear,which is unfavorable for the development of TC in areas with high frequencies of TRP-related TCs,are the factors that result in the decreasing trend of TRP.

Prevalence and Causes of Neonatal Mortality at Chu-Mel, Cotonou in 2023

Introduction: Neonatal mortality represents a global health problem that has been at the core of programs developed by the World Health Organization (WHO) for more than 30 years. In our country, it represents a real scourge and remains high despite the efforts made by the Ministry of Health. The goal of this study was to investigate the prevalence and causes of neonatal mortality at CHU-MEL of Cotonou in 2023. Material and Methods: This was a cross-sectional and descriptive study with retrospective data collection, carried out in the neonatology unit of the Mother and Child Teaching Hospital of Lagune (CHU-MEL) in Cotonou over a period of six months from January 1, 2023 to June 30, 2023. All neonates, premature or full-term, born alive and who died during hospitalization in the unit were included. Results: 211 cases of neonatal deaths were recorded among the 2884 neonates hospitalized in the unit during the study period, representing a hospital prevalence of 7.31%. Early neonatal mortality represented 81.5% of cases. The average age at admission was 4.6 days ± 5.3. The average weight of deceased neonates was 1609.08 ± 798.35 g. The most frequent reasons for hospitalization were represented by prematurity (60.66%) and respiratory distress (23.22%), respectively. Prematurity was the leading cause of neonatal mortality (41.7%), followed by neonatal infections (29.4%) and perinatal asphyxia (10.9%). Conclusion: The prevalence of neonatal mortality in the neonatology unit of CHU-MEL is high. Efforts to improve the quality of perinatal care departments must be intensified to reduce this prevalence.

Distribution and Formation Causes of PM_(2.5) and O_(3) Double High Pollution Events in China during 2013–20

Fine particulate matter(PM_(2.5))and ozone(O_(3))double high pollution(DHP)events have occurred frequently over China in recent years,but their causes are not completely clear.In this study,the spatiotemporal distribution of DHP events in China during 2013–20 is analyzed.The synoptic types affecting DHP events are identified with the Lamb–Jenkinson circulation classification method.The meteorological and chemical causes of DHP events controlled by the main synoptic types are further investigated.Results show that DHP events(1655 in total for China during 2013–20)mainly occur over the North China Plain,Yangtze River Delta,Pearl River Delta,Sichuan Basin,and Central China.The occurrence frequency increases by 5.1%during 2013–15,and then decreases by 56.1%during 2015–20.The main circulation types of DHP events are“cyclone”and“anticyclone”,accounting for over 40%of all DHP events over five main polluted regions in China,followed by southerly or easterly flat airflow types,like“southeast”,“southwest”,and“east”.Compared with non-DHP events,DHP events are characterized by static or weak wind,high temperature(20.9℃ versus 23.1℃)and low humidity(70.0%versus 64.9%).The diurnal cycles of meteorological conditions cause PM_(2.5)(0300–1200 LST,Local Standard Time=UTC+8 hours)and O_(3)(1500–2100 LST)to exceed the national standards at different periods of the DHP day.Three pollutant conversion indices further indicate the rapid secondary conversions during DHP events,and thus the concentrations of NO_(2),SO_(2) and volatile organic compounds decrease by 13.1%,4.7%and 4.4%,respectively.The results of this study can be informative for future decisions on the management of DHP events.

The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries

This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urbanization, invaded by non-local plants, or enclosed for individual use and by subdividing farmlands into subsequent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possible. Land fragmentation is one of the key reasons why the ability of most resources in East Africa becomes scarcer, and those remaining become “privatized” by more powerful community members—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further by affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation problems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighboring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a substantial increase in population density. The study review further explores the trend in the performance of agriculture by average farm sizes within the intervals of five years by highlighting their strong linkages and found that the average farm size has declined drastically, especially for Kenya. This can only mean that small farms kept becoming smaller and smaller and that there were more small-scale farmers. The results further depicted that the major and commonly cultivated food crops among the East African countries include maize, sorghum, rice, cassava, sweet potatoes, bananas, Irish potatoes, beans, peas, etc., with maize yields (Mt/ha) in 2003 for Uganda being the highest (1.79 Mt/ha) and the lowest in Rwanda (0.77 Mt/ha) respectively. Therefore, from the review results, recommendations are being made as to how the negative impacts of land fragmentation on agricultural productivity can be reduced or mitigated. One way is by community sensitization and awareness about the importance of land consolidation and its proposition on farm productivity.

Eternal Climate Change Patterns and the Causes and Countermeasures of Global Climate Change

It is an objective fact that the weather is unpredictable.Even the famous meteorologist,Academician Chu Ko Chen,has only a partial understanding of the changing laws of wind and rain.Even though ancient people summarized the 24 solar terms by observing the annual activities of the sun for a long time,because they ignored the impact of the activities of the moon on the Earth’s climate change on a small scale,the 24 solar terms they summarized often could not accurately predict the change of the Earth’s climate.Therefore,the author studied the influence of lunar activities on the Earth’s climate change,finds out the law of the influence of lunar activities on the Earth’s climate change on a small scale,and summarizes the eternal climate change pattern determined by the activities of the sun and the moon.In addition,the author also reveals the causes and countermeasures of global warming and the frequent occurrence of extreme weather as well as environmental change.

Rare causes of acute non-variceal upper gastrointestinal bleeding: A comprehensive review

Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Gastroenterologists and other involved clinicians are generally assisted by international guidelines in its management.However,NVUGIB due to peptic ulcer disease only is mainly addressed by current guidelines,with upper gastrointestinal endoscopy being recommended as the gold standard modality for both diagnosis and treatment.Conversely,the management of rare and extraordinary rare causes of NVUGIB is not covered by current guidelines.Given they are frequently lifethreatening conditions,all the involved clinicians,that is emergency physicians,diagnostic and interventional radiologists,surgeons,in addition obviously to gastroenterologists,should be aware of and familiar with their management.Indeed,they typically require a prompt diagnosis and treatment,engaging a dedicated,patient-tailored,multidisciplinary team approach.The aim of our review was to extensively summarize the current evidence with regard to the management of rare and extraordinary rare causes of NVUGIB.

Age-specific causes of upper gastrointestinal bleeding in children

The etiology of upper gastrointestinal bleeding(UGIB)varies by age,from newborns to adolescents,with some of the causes overlapping between age groups.While particular causes such as vitamin K deficiency and cow’s milk protein allergy are limited to specific age groups,occurring only in neonates and infants,others such as erosive esophagitis and gastritis may be identified at all ages.Furthermore,the incidence of UGIB is variable throughout the world and in different hospital settings.In North America and Europe,most UGIBs are nonvariceal,associated with erosive esophagitis,gastritis,and gastric and duodenal ulcers.In recent years,the most common causes in some Middle Eastern and Far Eastern countries are becoming similar to those in Western countries.However,variceal bleeding still predominates in certain parts of the world,especially in South Asia.The most severe hemorrhage arises from variceal bleeding,peptic ulceration,and disseminated intravascular coagulation.Hematemesis is a credible indicator of a UGI source of bleeding in the majority of patients.Being familiar with the most likely UGIB causes in specific ages and geographic areas is especially important for adequate orientation in clinical settings,the use of proper diagnostic tests, and rapid initiation of the therapy. The fundamental approach to the management of UGIBincludes an immediate assessment of severity, detecting possible causes, and providing hemodynamic stability,followed by early endoscopy. Unusual UGIB causes must always be considered when establishing a diagnosis inthe pediatric population because some of them are unique to children. Endoscopic techniques are of significantdiagnostic value, and combined with medicaments, may be used for the management of acute bleeding. Finally,surgical treatment is reserved for the most severe bleeding.

An Extreme Monsoonal Heavy Rainfall Event over Inland South China in June 2022: A Synoptic Causes Analysis

An extreme monsoonal heavy rainfall event lasted for nine days and recurred in the interior of northern south China from June 13 to 21, 2022. Using regional meteorological stations and ERA5 reanalysis data, the causes of this extreme monsoonal rainfall event in south China were analyzed and diagnosed. The results are shown as follows. A dominant South Asian high tended to be stable near the Qinghai-Tibet Plateau, providing favorable upper-level dispersion conditions for the occurrence of heavy rainfall in south China. A western Pacific subtropical high dominated the eastern part of the South China Sea, favoring stronger and more northward transport of water vapor to the northern part of south China at lower latitudes than normal. The continuous heavy precipitation event can be divided into two stages. The first stage(June 13-15) was the frontal heavy rainfall caused by cold air(brought by an East Asian trough)from the mid-latitudes that converged with a monsoonal airflow. The heavy rains occurred mostly in the area near a shear in front of the center of a synoptic-system-related low-level jet(SLLJ), and the jet stream and precipitation were strongest in the daytime. The second stage(June 16-21) was the warm-sector heavy rainfall caused by a South China Sea monsoonal low-level jet penetrating inland. The heavy rainfall occurred on the windward slope of the Nanling Mountains and in the northern part of a boundary layer jet(BLJ). The BLJ experienced five nighttime enhancements, corresponding well with the enhancement of the rainfall center, showing significant nighttime heavy rainfall characteristics. Finally, a conceptual diagram of inland-type warm-sector heavy rainfall in south China is summarized.

Omadacycline for the treatment of Legionella pneumophila pneumonia caused by drowning:a case report

Drowning is a major cause of preventable death and pathology worldwide.Every year,more than 295,000people die from accidental drowning.Ninety percent of accidental drowning deaths occur in low-and middleincome countries,and nearly half occur in people under the age of 25.

Postpartum Hemorrhage: Incidence, Causes and Maternal Outcomes at Muhimbili National Hospital, Tanzania—A Retrospective Descriptive Hospital-Based Study

Worldwide obstetric hemorrhage remains the leading cause of maternal mortality, accounting for over one quarter of maternal deaths. Over half of these deaths occur in Sub-Saharan Africa with mortality rates of 500 - 1000 per 100,000 births, compared to approximately 5 - 10 in developed countries. Over decades in Sub Saharan Africa preventive measures and treatment protocols have been made to reduce maternal mortality caused by PPH. While rates of postpartum hemorrhage have continued to rise, there is a need to evaluate if its etiology and patterns have changed over time. Broad Objective: This study aims at describing trends in incidence, causes and maternal outcomes of Postpartum Hemorrhage at Muhimbili National Hospital for a period of 7 years. Methodology: This is a retrospective descriptive hospital-based study that has included all cases of postpartum hemorrhage at Muhimbili National Hospital, a tertiary hospital in Tanzania from 2014 to 2020. The data was analyzed using SPSS Version 26 and presented using frequency tables, figures and percentages. The trends of postpartum hemorrhage over time were determined using chi-square test and P-value where less than 0.05 was considered statistically significant. Results: Overall, the incidence of postpartum hemorrhage has been fluctuating over the years with minimum of 1.78% and maximum of 2.87% with no statistical significance. Out of 1113 enrolled cases of PPH, 422 (37.9%) were attributed to genital tears followed by uterine atony 285 (25.6%). A statistically significant increase in linear trend was observed in the postpartum hemorrhage cases due to uterine atony, uterine rupture and sub analysis on genital tears (cervical tear). Overall, there was a statistically significant change in trend of maternal outcomes throughout the years, with a P-value < 0.001 and likelihood of complications increasing over time. Conclusion: The trend in the incidence of postpartum hemorrhage has been fluctuating over the years during the study period. The leading cause of postpartum hemorrhage was genital tears, followed by uterine atony with a significant increase in adverse maternal outcomes over the years. Continuous health education to medical personnel to improve timely and proper diagnosis of women in danger of PPH and timely referral, thus improve maternal morbidity and mortality.

The Effect of Coding Method on Cause-of-Death Rankings

Background: Cause-of-death rankings are often used for planning or evaluating health policy measures. In the European Union, some countries produce cause-of-death statistics by a manual coding of death certificates, while other countries use an automated coding system. The outcome of these two different methods in terms of the selected underlying cause of death for statistics may vary considerably. Therefore, this study explores the effect of coding method on the ranking of countries by major causes of death. Method: Age and sex standardized rates were extracted for 33 European (related) countries from the cause-of-death registry of the European Statistical Office (Eurostat). Wilcoxon’s rank sum test was applied to the ranking of countries by major causes of death. Results: Statistically significant differences due to coding method were identified for dementia, stroke and pneumonia. These differences could be explained by a different selection of dementia or pneumonia as underlying cause of death and by a different certification practice for stroke. Conclusion: Coding method should be taken into account when constructing or interpreting rankings of countries by cause of death.

Causes of gastrointestinal bleeding in children based on endoscopic evaluation at a tertiary care center in Bahrain

BACKGROUND Gastrointestinal bleeding(GIB)is a serious health problem worldwide,particularly during childhood.This can be an alarming sign of an underlying disease.Gastrointestinal endoscopy(GIE)is a safe method for the diagnosis and treatment of GIB in most cases.AIM To determine the incidence,clinical presentation,and outcomes of GIB in children in Bahrain over the last two decades.METHODS This was a retrospective cohort review of the medical records of children with GIB who underwent endoscopic procedures in the Pediatric Department at Salmaniya Medical Complex,Bahrain,between 1995 and 2022.Demographic data,clinical presentation,endoscopic findings,and clinical outcomes were recorded.GIB was classified into upper(UGIB)and lower(LGIB)GIB according to the site of bleeding.These were compared with respect to patients’sex,age,and nationality using the Fisher’s exact,Pearson’sχ2,or the Mann-Whitney U tests.RESULTS A total of 250 patients were included in this study.The median incidence was 2.6/100000 per year(interquartile range,1.4-3.7)with a significantly increasing trend over the last two decades (P < 0.0001). Most patients were males (n = 144, 57.6%). Themedian age at diagnosis was 9 years (5-11). Ninety-eight (39.2%) patients required upper GIEalone, 41 (16.4%) required colonoscopy alone, and 111 (44.4%) required both. LGIB was morefrequent (n = 151, 60.4%) than UGIB (n = 119, 47.6%). There were no significant differences in sex (P = 0.710), age (P = 0.185), or nationality (P = 0.525) between the two groups. Abnormalendoscopic findings were detected in 226 (90.4%) patients. The common cause of LGIB was inflammatorybowel disease (IBD) (n = 77, 30.8%). The common cause of UGIB was gastritis (n = 70, 28%).IBD and undetermined cause for bleeding were higher in the 10-18 years group (P = 0.026 and P =0.017, respectively). Intestinal nodular lymphoid hyperplasia, foreign body ingestion, andesophageal varices were more common in the 0-4 years group (P = 0.034, P < 0.0001, and P = 0.029,respectively). Ten (4%) patients underwent one or more therapeutic interventions. The medianfollow-up period was two years (0.5-3). No mortality was reported in this study.CONCLUSIONGIB in children is an alarming condition, whose significance is increasing. LGIB, commonly due toIBD, was more common than UGIB, commonly due to gastritis.

Analysis of the Causes of the Intensity Enhancement of the Typhoon “Tiange”

This paper analyzes the causes of the offshore strength enhancement of Typhoon Tiange (No. 1713) from four aspects: high and low layer divergence, vertical wind shear, southwest monsoon transport, offshore sea temperature and weak cold air. The conclusions are as follows: The high-level airflow divergence enhancement and positive vorticity advection in the offshore, strengthen the middle rise movement of the “Tiange”, and the ascending movement enhances the strength of the “Tiange” by strengthening the lower layer convergence;The high offshore sea temperature and sea temperature are changing temperature, which also has a certain effect on the strengthening of “Tiange” in the offshore;The strengthening of the southwest warm and humid airflow provides sufficient water vapor and energy for the development of “Tiange”, which is beneficial to the maintenance of the typhoon warm heart structure;The intrusion of weak cold air, enhanced the radiation cooperation of the lower typhoon disturbance, which is beneficial to the enhancement of “Tiange”.

Knowledge-enriched joint-learning model for implicit emotion cause extraction

Emotion cause extraction(ECE)task that aims at extracting potential trigger events of certain emotions has attracted extensive attention recently.However,current work neglects the implicit emotion expressed without any explicit emotional keywords,which appears more frequently in application scenarios.The lack of explicit emotion information makes it extremely hard to extract emotion causes only with the local context.Moreover,an entire event is usually across multiple clauses,while existing work merely extracts cause events at clause level and cannot effectively capture complete cause event information.To address these issues,the events are first redefined at the tuple level and a span-based tuple-level algorithm is proposed to extract events from different clauses.Based on it,a corpus for implicit emotion cause extraction that tries to extract causes of implicit emotions is constructed.The authors propose a knowledge-enriched jointlearning model of implicit emotion recognition and implicit emotion cause extraction tasks(KJ-IECE),which leverages commonsense knowledge from ConceptNet and NRC_VAD to better capture connections between emotion and corresponding cause events.Experiments on both implicit and explicit emotion cause extraction datasets demonstrate the effectiveness of the proposed model.

Causes of Strong Sandstorm Weather on March 15,2021 in Ulanqab City

The severe sandstorm process in Ulanqab,Inner Mongolia on March 15,2021 was analyzed and discussed from the aspects of weather facts,weather causes and dynamic diagnosis.The results show that the strong cold air in West Siberia rapidly moved eastward,and the surface cold front moved eastward to Ulanqab with significant warming in the previous period,resulting in gale and sandstorm weather.This severe sandstorm process occurred in basically stable atmospheric stratification.During the strong sandstorm and extremely strong sandstorm process on March 15,the strong warming in the early period near the surface led to the surface thermal instability,and sand was generated by the upward movement of the Mongolian cyclone.Over the upper northwest air stream,barocline disturbance developed unsteadily,and the upper cold advection stimulated the secondary circulation of front perpendicular to the surface;the surface cyclone turned into strong cold front,and then strong sandstorm weather occurred in Ulanqab.

Empowering women to combat osteoporosis:unveiling the causes,consequences,and control strategies

Osteoporosis is a common bone disease in women worldwide, leading to decreased bone density and an accelerated risk of fractures. The causes of osteoporosis in women include age (senile osteoporosis), menopause-associated hormonal changes, deficiencies in calcium and vitamin D, genetics, lifestyle factors, medical conditions, and some type of medications. The consequences of osteoporosis are colossal, consisting of fractures, decreased quality of life, psychological impacts, and economic burden. To effectively control the menace of osteoporosis in women, numerous strategies are advocated. Adequate calcium and vitamin D consumption through diet or supplements is vital. Regular weight-bearing activities and strength training that promote bone density. Maintaining a healthy life-style through avoiding smoking, limiting alcohol in-take and maintaining a wholesome body weight is essential. Hormone replacement therapy and some medications may be recommended in certain cases. Early detection through regular bone density and blood tests is crucial to lowering its impact. Creating a supportive network through educational programs and resources fosters awareness and empowerment. By engaging these strategies, women can be empowered to combat osteoporosis, reduce fracture risk, and build stronger bones for their overall well-being.

The Cause and Prevention of Major Earthquakes in the World

On February 6, 2023, a series of severe earthquakes occurred in eastern Turkey and neighboring areas of Syria. It was the largest earthquake in the world in more than a year, and the largest earthquake in the history of Turkey. Living under the fear of earthquakes, the people in Turkey and other earthquake zones have hoped again and again to change their fate, but they have to resign themselves to fate. Thus, the author analyzed the causes of large earthquakes such as Turkey earthquake, and found that some of the world’s potential seismic zones have been eroded by sea water or river water for a long time to create a series of surface faults. When the moon gets close to these faults, it will have a huge gravitational pull on them, and even cause the fault to move, resulting in strong earthquakes. Especially in some seismic zones, earthquakes are occurring more and more frequently and their intensity is getting bigger and bigger. The main reason is that the opening of the Arctic shipping route and the exploration and exploitation of oil and gas have caused the melting of the Arctic ice sheet and the loss of glaciers, which has led to the weakening of the Arctic vortex and the reduction of the compression ability of the polar vortices to the clouds, thus slowing down the rotation of the Earth and thus the revolution of the moon. So the moon gradually moves in a spiral toward the Earth;as the moon orbit close to the Earth, the moon’s gravity on the surface faults will gradually strengthen, so it is easy to cause the surface fault dislocations, resulting in frequent earthquakes or strong earthquakes. So the author puts forward some measures to prevent frequent and strong earthquakes.

The Causes and Applications of Code Switching Between Chinese and English in Social Intercourse

This paper examines the phenomenon of code switching between Chinese and English in China.It explores the causes,types,and applications of code switching,as well as the public’s attitudes towards it.The paper distinguishes between pathological and non-pathological code switching,and analyzes the corpus of code switching in Hong Kong.It also discusses how English as a dominant language affects the perception and use of code switching.The paper suggests that code switching is not only a linguistic but also an emotional process,and that speakers and listeners should be aware of their audience group when using code switching.

Causes of a Cold Wave Process Accompanied by Gale and a Drop in Temperature in Central Inner Mongolia

Based on the conventional high-and low-altitude and surface observation data,the weather analysis and diagnosis methods were applied to analyze the cold wave process of Ulanqab in January 2016 from the aspects of weather reality,circulation background,weather causes,and forecast test.The results show that strong cold air accumulated gradually near Lake Baikal and Central Siberia,affecting the city in a northwest path.During the cold wave process,the transverse trough moved southwards slowly at 500 hPa,and the ground cold high pressure was strong and stable.The cold air continued to move southwards,resulting in the strong cold wave and gale weather with a large impact range and long duration.The high-altitude jet at 300 hPa strengthened the cold wave pile,which was conducive to the outbreak of the cold wave.The intensity and location changes of the 500 hPa positive vorticity center,850 hPa cold advection region and 24-h ground pressure variation well showed the intensity of the cold wave process and the variation of the affected region.The influence of strong cold advection,ground positive pressure variation,and strong vertical wind shear were the main reasons for a strong drop in temperature and gale weather in this process.The test results of prediction reveal that the forecast value of the maximum temperature were relatively lower than the actual value,while the forecast of the minimum temperature was more accurate.The three warning signals were issued timely and accurately.The circulation pattern predicted by numerical models was more accurate in the early stage of the process,but there was an error in the late stage,and the forecast system moved slower than the actual situation.