Construction and Application of a Regional Kilometer-Scale Carbon Source and Sink Assimilation Inversion System(CCMVS-R)

CO_(2)is one of the most important greenhouse gases(GHGs)in the earth’s atmosphere.Since the industrial era,anthropogenic activities have emitted excessive quantities of GHGs into the atmosphere,resulting in climate warming since the 1950s and leading to an increased frequency of extreme weather and climate events.In 2020,China committed to striving for carbon neutrality by 2060.This commitment and China’s consequent actions will result in significant changes in global and regional anthropogenic carbon emissions and therefore require timely,comprehensive,and objective monitoring and verification support(MVS)systems.The MVS approach relies on the top-down assimilation and inversion of atmospheric CO_(2)concentrations,as recommended by the Intergovernmental Panel on Climate Change(IPCC)Inventory Guidelines in 2019.However,the regional high-resolution assimilation and inversion method is still in its initial stage of development.Here,we have constructed an inverse system for carbon sources and sinks at the kilometer level by coupling proper orthogonal decomposition(POD)with four-dimensional variational(4DVar)data assimilation based on the weather research and forecasting-greenhouse gas(WRF-GHG)model.Our China Carbon Monito ring and Verification Support at the Regional level(CCMVS-R)system can continuously assimilate information on atmospheric CO_(2)and other related information and realize the inversion of regional and local anthropogenic carbon emissions and natural terrestrial ecosystem carbon exchange.Atmospheric CO_(2)data were collected from six ground-based monito ring sites in Shanxi Province,China to verify the inversion effect of regio nal anthropogenic carbon emissions by setting ideal and real experiments using a two-layer nesting method(at 27 and 9 km).The uncertainty of the simulated atmospheric CO_(2)decreased significantly,with a root-mean-square error of CO_(2)concentration values between the ideal value and the simulated after assimilation was close to 0.The total anthropogenic carbon emissions in Shanxi Province in 2019 from the assimilated inversions were approximately 28.6%(17%-38%)higher than the mean of five emission inventories using the bottomup method,showing that the top-down CCMVS-R system can obtain more comprehensive information on anthropogenic carbon emissions.

Erlotinib combination with a mitochondria-targeted ubiquinone effectively suppresses pancreatic cancer cell survival

BACKGROUND Pancreatic cancer is a leading cause of cancer-related deaths.Increased activity of the epidermal growth factor receptor(EGFR)is often observed in pancreatic cancer,and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration.Nevertheless,erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes.We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential(Δψm),facilitate tumor cell uptake ofΔψm-sensitive agents,disrupt mitochondrial homeostasis,and subsequently trigger tumor cell death.Erlotinib has not been tested for this effect.AIM To determine whether erlotinib can elevateΔψm and increase tumor cell uptake ofΔψm-sensitive agents,subsequently triggering tumor cell death.METHODSΔψm-sensitive fluorescent dye was used to determine how erlotinib affectsΔψm in pancreatic adenocarcinoma(PDAC)cell lines.The viability of conventional and patient-derived primary PDAC cell lines in 2D-and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone(MitoQ),aΔψm-sensitive MitoQ.The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0.The preclinical efficacy of the twodrug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts.RESULTS Erlotinib elevatedΔψm in PDAC cells,facilitating tumor cell uptake and mitochondrial enrichment ofΔψm-sensitive agents.MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses,while erlotinib pretreatment potentiated low doses of MitoQ.SynergyFinder suggested that these drugs synergistically induced tumor cell lethality.Consistent with in vitro data,erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent.CONCLUSION Our findings suggest that a combination of erlotinib and MitoQ has the potential to suppress pancreatic tumor cell viability effectively.

Uncertainties of ENSO-related Regional Hadley Circulation Anomalies within Eight Reanalysis Datasets

El Nino-Southern Oscillation(ENSO),the leading mode of global interannual variability,usually intensifies the Hadley Circulation(HC),and meanwhile constrains its meridional extension,leading to an equatorward movement of the jet system.Previous studies have investigated the response of HC to ENSO events using different reanalysis datasets and evaluated their capability in capturing the main features of ENSO-associated HC anomalies.However,these studies mainly focused on the global HC,represented by a zonal-mean mass stream function(MSF).Comparatively fewer studies have evaluated HC responses from a regional perspective,partly due to the prerequisite of the Stokes MSF,which prevents us from integrating a regional HC.In this study,we adopt a recently developed technique to construct the three-dimensional structure of HC and evaluate the capability of eight state-of-the-art reanalyses in reproducing the regional HC response to ENSO events.Results show that all eight reanalyses reproduce the spatial structure of HC responses well,with an intensified HC around the central-eastern Pacific but weakened circulations around the Indo-Pacific warm pool and tropical Atlantic.The spatial correlation coefficient of the three-dimensional HC anomalies among the different datasets is always larger than 0.93.However,these datasets may not capture the amplitudes of the HC responses well.This uncertainty is especially large for ENSO-associated equatorially asymmetric HC anomalies,with the maximum amplitude in Climate Forecast System Reanalysis(CFSR)being about 2.7 times the minimum value in the Twentieth Century Reanalysis(20CR).One should be careful when using reanalysis data to evaluate the intensity of ENSO-associated HC anomalies.

Adaptive H_(∞)Filtering Algorithm for Train Positioning Based on Prior Combination Constraints

To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior information with other sensor information in the form of constraints.Firstly,the train precise track constraint method of the train is proposed,and the plane position constraint and train motion state constraints are analysed.A model for combining prior information with constraints is established.Then an adaptive H∞filter with combination constraints is derived based on the adaptive adjustment method of the robustness factor.Finally,the positioning effect of the proposed algorithm is simulated and analysed under the conditions of a straight track and a curved track.The results show that the positioning accuracy of the algorithm with constrained filtering is significantly better than that of the algorithm without constrained filtering and that the algorithm with constrained filtering can achieve better performance when combined with track and condition information,which can significantly reduce the train positioning error.The effectiveness of the proposed algorithm is verified.

Individual alcohol consumption by the population of Russia versus regional living conditions

Background:There are substantial regional differences in drinking alcohol in Russia,both at the population and individual levels.However,the causes of these differences have not been studied yet.Objective:The goal of our study was to examine the effect of regional living conditions on individual alcohol consumption by the population of Russia.Methods:For the analysis,we used data from a cross-sectional epidemiological study conducted in 2013-2014.The final analytical sample included 18,130 people aged 25-64 years.We conducted the interviews face to face,based on which any drinking in the last year,as well as alcohol abuse,were considered as a response.Alcohol abuse was recorded when the respondent consumed 5.75 or more grams of pure ethanol per day(75th percentile of average daily alcohol consumption among alcohol drinkers).The assessment of the regional living conditions was accomplished via integral indexing,which was previously performed based on publicly available data for 2010-2014.Associations were assessed using generalized scoring equations with unchanging standard errors.The associations were expressed by odds ratios(OR)and 95%confidence intervals(C).Results:Deterioration of social conditions and increase in demographic depression in the region of residence increased the odds of any drinking(OR 1.51,95%CI:1.33 to 1.72,P<0.001 and OR 1.22,95%CI:1.05 to 1.41,P=0.oo9,respectively).The odds of alcohol abuse increased with the deterioration of social living conditions and the growth of the industrial development in the region:OR 1.35,95%CI:1.14 to 1.59,P<0.001 and OR 1.16,95%CI:1.05 to 1.28,P=0.002,respectively.Conclusion:Our analysis allowed assessing the impact of the regional living conditions on individual drinking alcohol in the population of Russia.

Combinational therapy with Myc decoy oligodeoxynucleotides encapsulated in nanocarrier and X-irradiation on breast cancer cells

The Myc gene is the essential oncogene in triple-negative breast cancer(TNBC).This study investigates the synergistic effects of combining Myc decoy oligodeoxynucleotides-encapsulated niosomes-selenium hybrid nanocarriers with X-irradiation exposure on the MDA-MB-468 cell line.Decoy and scramble ODNs for Myc transcription factor were designed and synthesized based on promoter sequences of the Bcl2 gene.The nanocarriers were synthesized by loading Myc ODNs and selenium into chitosan(Chi-Se-DEC),which was then encapsulated in niosome-nanocarriers(NISM@Chi-Se-DEC).FT-IR,DLS,FESEM,and hemolysis tests were applied to confirm its characterization and physicochemical properties.Moreover,cellular uptake,cellular toxicity,apoptosis,cell cycle,and scratch repair assays were performed to evaluate its anticancer effects on cancer cells.All anticancer assessments were repeated under X-ray irradiation conditions(fractionated 2Gy).Physicochemical characteristics of niosomes containing SeNPs and ODNs showed that it is synthesized appropriately.It revealed that the anticancer effect of NISM@Chi-Se-DEC can be significantly improved in combination with X-ray irradiation treatment.It can be concluded that NISM@Chi-Se-DEC nanocarriers have the potential as a therapeutic agent for cancer treatment,particularly in combination with radiation therapy and in-vivo experiments are necessary to confirm the efficacy of this nano-drug.

LociScan,a tool for screening genetic marker combinations for plant variety discrimination

To reduce the cost and increase the efficiency of plant genetic marker fingerprinting for variety discrimination,it is desirable to identify the optimal marker combinations.We describe a marker combination screening model based on the genetic algorithm(GA)and implemented in a software tool,Loci Scan.Ratio-based variety discrimination power provided the largest optimization space among multiple fitness functions.Among GA parameters,an increase in population size and generation number enlarged optimization depth but also calculation workload.Exhaustive algorithm afforded the same optimization depth as GA but vastly increased calculation time.In comparison with two other software tools,Loci Scan accommodated missing data,reduced calculation time,and offered more fitness functions.In large datasets,the sample size of training data exerted the strongest influence on calculation time,whereas the marker size of training data showed no effect,and target marker number had limited effect on analysis speed.

Regional Digital Financial Services Security Clinic for Asia Pacific Region

April 24-25, Seoul, Republic of Korea The International Telecommunication Union(ITU) is organizing the Regional Digital Financial Services Security Clinic for Asia Pacific Region on April 24-25, 2024 in Seoul, Republic of Korea. The event is being jointly held with FNSV Korea and the Korean Fintech Center.

A Clinical Study to Assess the Effectiveness of Oral Combination Kit Therapy in Syndromic Management of Abnormal Vaginal Discharge (FEMINE Study) in Kinshasa, Democratic Republic of Congo

Background: Vaginal discharge is one of most common and nagging problems that women face. About 20% - 25% of women who visit gynecology department complain of vaginal discharge and leucorrhoea. An orally administered combination kit, containing 2 g secnidazole, 1 g azithromycin and 150 mg fluconazole (Azimyn FS Kit), has been successfully evaluated in clinical trials and used in several countries for management syndromic vaginal discharge due to infections. Methods: This is a longitudinal study which aimed to verify the clinical efficacy of the combined oral kit containing secnidazole, azithromycin and fluconazole (Azimyn FS Kit®) in the syndromic treatment of abnormal vaginal discharge in patients received in outpatient consultations in Kinshasa/DR Congo from March to September 2023. Results: Majority of patients had whitish vaginal discharge (51.6%) of average abundance (56.2%), accompanied by pruritus in 72.1% of cases, and dyspareunia in 23.5% of cases and hypogastralgia in 40.2% of cases. One week after treatment with the Azimyn FS® combined kit, at the greatest majority of patients (97.3%), abnormal vaginal discharge had decreased by more than 50% (84.1%). Two weeks after treatment with the Azimyn FS® combined kit, almost all patients (97.3%) no longer had abnormal vaginal discharge which had completely disappeared. Conclusion: A single dose of secnidazole, azithromycin and fluconazole in the form of an oral combi-kit (Azimyn FS Kit) has shown excellent therapeutic effectiveness in the syndromic treatment of abnormal vaginal discharge wherein patients were treated without diagnostic confirmation.

Resilience-Oriented Load Restoration Method and Repair Strategies for Regional Integrated Electricity-Natural Gas System

The rising frequency of extreme disaster events seriously threatens the safe and secure operation of the regional integrated electricity-natural gas system(RIENGS).With the growing level of coupling between electric and natural gas systems,it is critical to enhance the load restoration capability of both systems.This paper proposes a coordinated optimization strategy for resilience-enhanced RIENGS load restoration and repair scheduling and transforms it into a mixed integer second-order cone programming(MISOCP)model.The proposed model considers the distribution network reconfiguration and the coordinated repair strategy between the two systems,minimizing the total system load loss cost and repair time.In addition,a bi-directional gas flow model is used to describe the natural gas system,which can provide the RIENGS with more flexibility for load restoration during natural gas system failure.Finally,the effectiveness of the proposed approach is verified by conducting case studies on the test systems RIENGS E13-G7 and RIENGS E123-G20.

Specialization and Coordination: New Paradigm, Theory, and Path for Regional Development

In its new development stage,China seeks to derive new dynamism from reform and opening up at a higher level to boost consumption and services.This process coincides with a further differentiation of comparative advantages across regions.Economic activity and population will continue to concentrate in clusters in coastal and central cities amid a continuous outflow of population from remote areas.Development expansion from coastal to interior regions and from central cities to the periphery will promote a new regional development paradigm of“dual centers and periphery”.Therefore,China’s regional development strategy should follow the new theory of seeking relative equilibrium amid development,identify regions of population inflow and outflow,and explore a new development path of regional specialization and coordination.By deepening market reforms and increasing central government coordination,the country is poised to improve the spatial allocation of resources and unleash institutional dividends in the process of developing a unified national market.

Complex Regional Pain Syndrome: Outpatient Pain Management in the Chronic Setting: A Case Report

Background: Complex Regional Pain Syndrome (CRPS), previously known as reflex sympathetic dystrophy and causalgia, is a neuropathic pain condition that usually develops after an injury to an extremity. CRPS can be a debilitating condition with high levels of pain and reduced function. Aim: This case report aims to discuss the multimodal approach in the management of a patient who presented with ongoing poorly controlled pain secondary to CRPS from an injury that happened years prior. Case Presentation: A 45-year-old female was involved in a motor vehicle accident where her right leg was injured. She underwent several surgeries and developed CRPS that significantly reduced her mobility and quality of life. She presented to the pain clinic years after her initial injury and a multimodal regimen was started for her resulting in significantly improved function. Conclusion: CRPS can be a severely debilitating condition. While early diagnosis and management are important, ongoing management in the outpatient chronic pain setting is important in maintaining a good level of function.

Advances in extracellular vesicle-based combination therapies for spinal cord injury

Spinal cord injury is a severe insult to the central nervous system that causes persisting neurological deficits.The currently available treatments involve surgical,medical,and rehabilitative strategies.However,none of these techniques can markedly reverse neurological deficits.Recently,extracellular vesicles from various cell sources have been applied to different models of spinal cord injury,thereby generating new cell-free therapies for the treatment of spinal cord injury.However,the use of extracellular vesicles alone is still associated with some notable shortcomings,such as their uncertainty in targeting damaged spinal cord tissues and inability to provide structural support to damaged axons.Therefore,this paper reviews the latest combined strategies for the use of extracellular vesicle-based technology for spinal cord injury,including the combination of extracellular vesicles with nanoparticles,exogenous drugs and/or biological scaffold materials,which facilitate the targeting ability of extracellular vesicles and the combinatorial effects with extracellular vesicles.We also highlight issues relating to the clinical transformation of these extracellular vesicle-based combination strategies for the treatment of spinal cord injury.

Heterogeneous information phase space reconstruction and stability prediction of filling body–surrounding rock combination

Traditional research believes that the filling body can effectively control stress concentration while ignoring the problems of unknown stability and the complex and changeable stress distribution of the filling body–surrounding rock combination under high-stress conditions.Current monitoring data processing methods cannot fully consider the complexity of monitoring objects,the diversity of monitoring methods,and the dynamics of monitoring data.To solve this problem,this paper proposes a phase space reconstruction and stability prediction method to process heterogeneous information of backfill–surrounding rock combinations.The three-dimensional monitoring system of a large-area filling body–surrounding rock combination in Longshou Mine was constructed by using drilling stress,multipoint displacement meter,and inclinometer.Varied information,such as the stress and displacement of the filling body–surrounding rock combination,was continuously obtained.Combined with the average mutual information method and the false nearest neighbor point method,the phase space of the heterogeneous information of the filling body–surrounding rock combination was then constructed.In this paper,the distance between the phase point and its nearest point was used as the index evaluation distance to evaluate the stability of the filling body–surrounding rock combination.The evaluated distances(ED)revealed a high sensitivity to the stability of the filling body–surrounding rock combination.The new method was then applied to calculate the time series of historically ED for 12 measuring points located at Longshou Mine.The moments of mutation in these time series were at least 3 months ahead of the roadway return dates.In the ED prediction experiments,the autoregressive integrated moving average model showed a higher prediction accuracy than the deep learning models(long short-term memory and Transformer).Furthermore,the root-mean-square error distribution of the prediction results peaked at 0.26,thus outperforming the no-prediction method in 70%of the cases.

Combination treatment of inflammatory bowel disease:Present status and future perspectives

The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical gastroenterologist.It seems to be no exaggeration to say that in these patients,not only the scientific background of the gastroenterologist is tested,but also the abundance of“gifts”that he should possess(insight,intuition,determ-ination,ability to take initiative,etc.)for the successful outcome of the treatment.In daily clinical practice,depending on the severity of the attack,IBD is treated with one or a combination of two or more pharmaceutical agents.These combin-ations include not only the first-line drugs(e.g.,mesalazine,corticosteroids,antibiotics,etc)but also second-and third-line drugs(immunosuppressants and biologic agents).It is a fact that despite the significant therapeutic advances there is still a significant percentage of patients who do not satisfactorily respond to the treatment applied.Therefore,a part of these patients are going to surgery.In recent years,several small-size clinical studies,reviews,and case reports have been published combining not only biological agents with other drugs(e.g.,immunosuppressants or corticosteroids)but also the combination of two biologi-cal agents simultaneously,especially in severe cases.In our opinion,it is at least a strange(and largely unexplained)fact that we often use combinations of drugs in a given patient although studies comparing the simultaneous administration of two or more drugs with monotherapy are very few.As mentioned above,there is a timid tendency in the literature to combine two biological agents in severe cases unresponsive to the applied treatment or patients with severe extraintestinal manifestations.The appropriate dosage,the duration of the administration,the suitable timing for checking the clinical and laboratory outcome,as well as the treatment side-effects,should be the subject of intense clinical research shortly.In this editorial,we attempt to summarize the existing data regarding the already applied combination therapies and to humbly formulate thoughts and suggestions for the future application of the combination treatment of biological agents in a well-defined category of patients.We suggest that the application of biomarkers and artificial intelligence could help in establishing new forms of treatment using the available modern drugs in patients with IBD resistant to treatment.

Coupling coordinated development among digital economy,regional innovation,and talent employment:A case study in the Hangzhou Metropolitan Circle,China

Coordinative development across various systems,particularly the economic,social,cultural,and human resources subsystems,is a key aspect of urban sustainability and has a direct impact on the quality of urbanization.The Hangzhou Metropolitan Circle,comprising Hangzhou City,Huzhou City,Jiaxing City,and Shaoxing City,was the first metropolitan circle approved by the National Development and Reform Commission(NDRC)as a demonstration of economic transformation in China.To evaluate the coupling coordination degree of the four cities and analyze the coordinative development in three systems(including digital economy,regional innovation,and talent employment),we collected panel data during 2015–2022 from these four cities.The development level of the three systems was evaluated by the standard deviation method and comprehensive development index.The results are as follows:(1)the level of coupling coordinated development of the three systems in the Hangzhou Metropolitan Circle was relatively low;(2)the coupling coordination degree of the four cities in the Hangzhou Metropolitan Circle showed significant regional differences,among which Hangzhou City was in the leading position,and Huzhou,Jiaxing,and Shaoxing cities made steady but slow progress in the coupling development of the three systems;and(3)the development of digital economy and talent employment needs to be strengthened.This study contributes to the coordinative development of Hangzhou Metropolitan Circle by innovatively focusing on the coupling coordination relationship among digital economy,regional innovation,and talent employment,which also meets the industrial layout of Hangzhou Metropolitan Circle.In this way,the optimal allocation and sustainable development of digital economy,regional innovation,and talent employment in the Hangzhou Metropolitan Circle can be achieved.

Optimal Operation Strategy of Electricity-Hydrogen Regional Energy System under Carbon-Electricity Market Trading

Given the“double carbon”objective and the drive toward low-carbon power,investigating the integration and interaction within the carbon-electricity market can enhance renewable energy utilization and facilitate energy conservation and emission reduction endeavors.However,further research is necessary to explore operational optimization methods for establishing a regional energy system using Power-to-Hydrogen(P2H)technology,focusing on participating in combined carbon-electricity market transactions.This study introduces an innovative Electro-Hydrogen Regional Energy System(EHRES)in this context.This system integrates renewable energy sources,a P2H system,cogeneration units,and energy storage devices.The core purpose of this integration is to optimize renewable energy utilization and minimize carbon emissions.This study aims to formulate an optimal operational strategy for EHRES,enabling its dynamic engagement in carbon-electricity market transactions.The initial phase entails establishing the technological framework of the electricity-hydrogen coupling system integrated with P2H.Subsequently,an analysis is conducted to examine the operational mode of EHRES as it participates in carbon-electricity market transactions.Additionally,the system scheduling model includes a stepped carbon trading price mechanism,considering the combined heat and power generation characteristics of the Hydrogen Fuel Cell(HFC).This facilitates the establishment of an optimal operational model for EHRES,aiming to minimize the overall operating cost.The simulation example illustrates that the coordinated operation of EHRES in carbon-electricity market transactions holds the potential to improve renewable energy utilization and reduce the overall system cost.This result carries significant implications for attaining advantages in both low-carbon and economic aspects.

Characteristics of transfer zones under the influence of preexisting faults and regional stress transformation:Wenchang A subsag,Zhujiang River Mouth Basin,northern South China Sea

A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation.Based on the systematic analysis of 3D seismic data and hydrocarbon accumulation conditions,the geometry,kinematics,and reservoir control of a large synthetic overlapping transfer zone in the south of the Wenchang A subsag in the Zhujiang(Pearl)River Mouth basin were investigated.Results indicate that the development and evolution of the transfer zone was controlled by the interaction between pre-existing faults and regional stress transformation.The intense rifting of the main faults of the transfer zone controlled the development of source rocks and faultcontrolled slope break paleogeomorphology.The strike-slip overprint since the Oligocene is conducive to the formation of a large-scale fault-anticline trap,and the secondary faults in the transfer zone contribute to the hydrocarbon transportation.The conjugate intersection area of the NE-and NW-trending faults offers more opportunity for hydrocarbon migration and accumulation.

Regional Brand and High-quality Development of Fruits in Ethnic Areas of the Yangtze River Economic Belt under the Greater Food Approach

Establishing the Greater Food Approach and promoting the Yangtze River Economic Belt s national major regional development strategy can better support and serve the agricultural power and Chinese-style modernization.This paper introduces the characteristics of fruit industry in 16 autonomous prefectures and 47 autonomous counties under the jurisdiction of the Yangtze River Economic Belt.It studies the intellectual property resources of brand marks from the aspects of geographical indications,collective trademarks,certification trademarks,well-known trademarks in China and national design patents,and analyzes the main problems of brand and high-quality development of fruit industry in these ethnic autonomous areas.Finally,it puts forward some strategies,such as improving the protection of intellectual property rights of geographical indications,using intellectual property rights of brand signs,building modern seed industry upgrading project,drawing lessons from the experience of thousand villages demonstration project,ensuring that large-scale poverty does not occur,and building a diversified food supply system.

External Otitis: Epidemiological, Clinical, Etiological, and Therapeutic Aspects at the Oto-Rhino-Laryngology Department of Mamou Regional Hospital

Introduction: External otitis (OE) is an acute or chronic inflammation or infection of the external ear resulting from an imbalance in the external auditory canal secondary to microtrauma, maceration, eczema, or a foreign body in the external auditory canal. Objective: To study cases of external otitis at the Mamou Regional Hospital. Materials and Methods: This was a prospective descriptive study conducted over a period of six (6) months from July 1st to December 31st, 2016. It included all patients admitted to the ENT department of the Mamou Regional Hospital. Results: During the study period, 712 patients were admitted to the department for various pathologies, of which 103 met our selection criteria, representing a frequency of 14.46%. The mean age of the patients was 33.74 years with a range of 1 to 90 years. Males predominated in the sample, accounting for 59.22%. The vast majority of patients resided in urban areas, constituting 61.17% of the sample. In our study, all patients consulted for otalgia (100%), and over half (53.39%) for hypoacusis. We formally identified rhinitis in 66.66% of cases, while diabetes was found in only 4 patients (11.11%). Otomycosis was the most commonly identified condition (53.39%), followed by furuncles (33.98%). Ear drops containing antibiotics were administered to all patients, although 66.60% received antibiotic therapy. Conclusion: External otitis is a relatively common condition, particularly among children and the elderly. Diagnosis can be made based on pain upon traction of the pinna and pressure on the tragus.