Plant biofertilization involves introducing compounds containing living mi-croorganisms into the coating medium to sustainably enhance plant production and soil health. This is a complex process that undergoes multipl...Plant biofertilization involves introducing compounds containing living mi-croorganisms into the coating medium to sustainably enhance plant production and soil health. This is a complex process that undergoes multiple stages of development before yielding a final product. The final biofertilizer is used by legumes-protein-rich crops in symbiosis with rhizobia to enable biological nitrogen fixation increasing natural soil fertility. This study aims to determine the optimal formulation of a rhizobial biofertilizer to improve the performance of soybean (Glycine max L. cv. Docko). To this end, soybean seeds obtained from IRAD were coated with different formulations derived from locally sourced materials. Palm kernel oil was used as an adhesive in one group, while corn powder served as an adhesive in another. The coated seeds were then sown in the field. The results indicate that the combination of pigeon pea powder + sugarcane molasses, with palm kernel oil as an adhesive, produced the best nodulation (nitrogen fixation). This formulation also led to significant improvements in growth (+350%) and total nitrogen content (+1100%) compared to the bacterial broth inoculum control (B0) (P ≤ 0.01). These findings represent a significant advancement in improving nitrogen-fixing bacterial inoculants and enhancing soil fertility for the sustainable cultivation of soybeans in this tropical soil.展开更多
Background: In children, acute bacterial rhinosinusitis (ABRS) is often complicated by ophthalmological and/or neurological involvement. These complications should be known and recognized, as they require urgent treat...Background: In children, acute bacterial rhinosinusitis (ABRS) is often complicated by ophthalmological and/or neurological involvement. These complications should be known and recognized, as they require urgent treatment with intravenous antibiotics and close in-hospital monitoring. In this study, we aimed to identify the main risk factors associated with the development of complications in children aged 2 - 17 years with ABRS. Methods: We conducted a retrospective cohort study of patients with ABRS complications in a primary hospital. Participants were divided into two groups: the control group comprising patients without complications (Group 1, n = 82) and the study group comprising patients with complications requiring hospitalization (Group 2, n = 41). We assessed the sociodemographic, clinical, and imaging data of both groups. Using multivariate logistic regression, we assessed risk factors of ABRS complications. Results: No socio-demographic characteristics were associated with ABRS complications (p ≥ 0.05). Factors associated with complications were delay in consultation (t = 5.282;p Conclusions: Intracranial and extracranial complications of ABRS in children have become rare in our setting. These complications can be serious and potentially fatal. Risk factors of these complications are delays in consultation, the presence of ophthalmological signs, and more than one affected sinus. Controlling modifiable factors would improve the treatment success of ABRS complications in children.展开更多
The prediction of the fracture plane orientation in fatigue is a scientific topic and remains relevant for every type of material. However, in this work, we compared the orientation of the fracture plane obtained expe...The prediction of the fracture plane orientation in fatigue is a scientific topic and remains relevant for every type of material. However, in this work, we compared the orientation of the fracture plane obtained experimentally through tests on specimens under multiaxial loading with that calculated by the variance method. In the statistical approach criteria, several methods have been developed but we have presented only one method, namely the variance method using the equivalent stress. She assumes that the fracture plane orientation is the one on which the variance of the equivalent stress is maximum. Three types of equivalent stress are defined for this method [1]: normal stress, shear stress and combined normal and shear stress. The results obtained were compared with experimental results for multiaxial cyclic stress states, and it emerges that the variance method for the case of combined loading is conservative as it gives a better prediction of the fracture plane.展开更多
The waveguide which is at the center of our concerns in this work is a strongly flattened waveguide, that is to say characterized by a strong dispersion and in addition is strongly nonlinear. As this type of waveguide...The waveguide which is at the center of our concerns in this work is a strongly flattened waveguide, that is to say characterized by a strong dispersion and in addition is strongly nonlinear. As this type of waveguide contains multiple dispersion coefficients according to the degrees of spatial variation within it, our work in this article is to see how these dispersions and nonlinearities each influence the wave or the signal that can propagate in the waveguide. Since the partial differential equation which governs the dynamics of propagation in such transmission medium presents several dispersion and nonlinear coefficients, we check how they contribute to the choices of the solutions that we want them to verify this nonlinear partial differential equation. This effectively requires an adequate choice of the form of solution to be constructed. Thus, this article is based on three main pillars, namely: first of all, making a good choice of the solution function to be constructed, secondly, determining the exact solutions and, if necessary, remodeling the main equation such that it is possible;then check the impact of the dispersion and nonlinear coefficients on the solutions. Finally, the reliability of the solutions obtained is tested by a study of the propagation. Another very important aspect is the use of notions of probability to select the predominant solutions.展开更多
In this article, we study the impacts of nonlinearity and dispersion on signals likely to propagate in the context of the dynamics of four-wave mixing. Thus, we use an indirect resolution technique based on the use of...In this article, we study the impacts of nonlinearity and dispersion on signals likely to propagate in the context of the dynamics of four-wave mixing. Thus, we use an indirect resolution technique based on the use of the iB-function to first decouple the nonlinear partial differential equations that govern the propagation dynamics in this case, and subsequently solve them to propose some prototype solutions. These analytical solutions have been obtained;we check the impact of nonlinearity and dispersion. The interest of this work lies not only in the resolution of the partial differential equations that govern the dynamics of wave propagation in this case since these equations not at all easy to integrate analytically and their analytical solutions are very rare, in other words, we propose analytically the solutions of the nonlinear coupled partial differential equations which govern the dynamics of four-wave mixing in optical fibers. Beyond the physical interest of this work, there is also an appreciable mathematical interest.展开更多
Introduction: Arteriovenous malformation is a rare pathology, often discovered accidentally in children. Generally, it presents as an intra-parenchymal hematoma following rupture of the affected vessels. The risk of r...Introduction: Arteriovenous malformation is a rare pathology, often discovered accidentally in children. Generally, it presents as an intra-parenchymal hematoma following rupture of the affected vessels. The risk of rupture is linked to the volume of the malformation, its cortical location and venous drainage. In literature, few cases of rupture have been reported in cases of meningitis, but none are associated with a brain abscess. Objective: To report a case of an intraparenchymal hemorrhage due to rupture of an arteriovenous malformation with an associated brain abscess. Observation: The authors report the case of a 2-year-old child, admitted for impaired state of consciousness associated with a right hemiparesis and seizures in a febrile context. Clinical evaluation revealed a Blantyre score of 3, fever at 40˚C, divergent strabismus of the right eye, a right pyramidal syndrome and meningeal irritative syndrome. Cerebral CT scan revealed a left fronto-parietal intra-parenchymal hematoma and a right occipital ring-enhanced lesion, suggesting a brain abscess. An MRI suggested a probable rupture of an arteriovenous malformation resulting in the intra-parenchymal hematoma. Management consisted of craniotomy to evacuate the intra-parenchymal hematoma, antibiotic therapy with vancomycin and ceftriaxone at meningeal doses. Histopathological analysis of the intraoperative sample revealed an arteriovenous malformation. The postoperative course was marked by regression of hyperthermia, persistence of spasticity, irritability and clonic movement of the right lower limb. These were managed with baclofen, phenobarbital, and ergotherapy. We observed a regression of spasticity and improved motor skills in the right limbs. At 6 months follow-up, child could interact with his social environment despite aphasia, regression of spasticity and right hemiparesis. Conclusion: Rupture of arteriovenous malformations can be enhanced by neuro-meningeal infections and particularly brain abscesses. Cerebrovascular complications of these conditions mostly have unfavorable outcomes and neurological sequelae.展开更多
Abortion is one of the leading causes of maternal death in Cameroon, despite numerous policies and strategies put in place to reduce it by 2030.This study aims to describe the epidemiologic aspects of abortions within...Abortion is one of the leading causes of maternal death in Cameroon, despite numerous policies and strategies put in place to reduce it by 2030.This study aims to describe the epidemiologic aspects of abortions within hospitals in the city of Yaoundé in 2023. Methods: This was a descriptive cross-sectional study with prospective data collection in the maternity wards of the Yaoundé Gynaeco-Obstetric and Paediatric Hospital, and the Yaoundé Central Hospital for 7 months, from the 1st of November 2022 to the 31st of May 2023. The variables studied were demographic and clinical characteristics, means of recourse and post-abortion contraception. The frequency of abortions was calculated as the ratio of the number of abortions to the number of deliveries. The calculation of numbers and frequencies was used to describe the study population, and to highlight the sociodemographic and clinical characteristics of the patients recruited. Quantitative variables were expressed as mean ± standard deviation. Data were collected numerically and classified according to type, then analyzed using Epi-info version 7.2 software. Microsoft Office Excel 2013 was used to produce figures and tables. Results: During the study period, 169 patients were selected out of 1882 patients who had consulted for gynaecological emergencies;but only 164 of them accepted to participate. The frequency of abortions was 9.6% (169/1882). The age group of 25 to 29 years was the most represented, with 29.3% (48/164). They were mainly single 76.2% (125/164), and housewives 33.5% (55/164). The notion of previous abortion was found in 30.5% (50/164) of them. Approximately 19.5% of patients (32/164) reported to have conceived while using contraception, 56.2% of whom (18/32) used male condoms. At the time of admission to the emergency unit, the predominant symptom was bleeding in 70.7% of cases. The abortions were mainly spontaneous, in 75% of cases (123/164). In cases of induced abortions, 24.4% (10/41) of them took place after 14 weeks. Unexpected pregnancy was the main reason for termination in 46.3% of cases (19/41). Regarding induced abortion, 58.54% (24/41) of them resorted to voluntary medical termination. The mortality rate was 1.2%. The acceptability rate of a modern contraceptive method before discharge was 31.7%. Conclusion: Although frequent in our environment, data relating to abortion remain under-evaluated. Abortions occur mainly among young, single women, with a still very high proportion of induced abortions. The acceptability of post-abortion contraception remains poor. Prevention of unwanted pregnancies and risk factors is necessary to reduce the burden of abortions in low-income countries.展开更多
From the ethyl acetate extract of the medicinal plant Graptophyllum glandulosum Turrill, five known compounds: Lupeol (1), Oleanolic acid (2), Chrysoeriol (3), N-methyl-isonicotinamide (4) and β-sitosterol 3-O-β-D-g...From the ethyl acetate extract of the medicinal plant Graptophyllum glandulosum Turrill, five known compounds: Lupeol (1), Oleanolic acid (2), Chrysoeriol (3), N-methyl-isonicotinamide (4) and β-sitosterol 3-O-β-D-glucopyranoside (5) were isolated. In addition, oxidation reactions carried out on lupeol (1) yielded two semi-synthetic compounds, including a previously unreported: (20R)-formyloxy-29-nor-lupan-3-one (1b) and one other well-known Lupenone (1a). The structures of natural and semi-synthetic compounds were determined by analysis of 1D-(1H, 13C), 2D-(COSY, HSQC and HMBC) NMR data in conjunction with mass spectrometry (TOFESIMS and HR-TOFESIMS) and by comparison with the reported data. The evaluation of antimicrobial activities of substrate (1) as well as semi-synthetic derivatives (1a and 1b) using broth microdilution method showed that compound 1b was the most active (16 ≤ MIC ≤ 32 μg/mL) against Escherichia coli, Staphylococcus aureus and Candida albicans compared to the starting material 1 (16 ≤ MIC ≤ 64 μg/mL) and derivative 1a (32 ≤ MIC ≤ 64 μg/mL).展开更多
The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the coll...The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the collection of wastewater samples. Their analysis revealed specific pollutant loads, including loads of BOD5 3.6966 kgO<sub>2</sub>/day and COD of 12.8775 kgO<sub>2</sub>/day, which were central to the design phase. Following a rigorous assessment of the existing sanitation infrastructure, constructed wetland (CWs) emerged as the most appropriate ecological solution. This system, valued for its ability to effectively remove contaminants, was tailored to the specific needs of the site. Consequently, the final design of the filter extends over 217.16 m<sup>2</sup>, divided into two cells of 108.58 m<sup>2</sup> each, with dimensions of 12.77 m in length and 8.5 m in width. The depth of the filtering medium is approximately 0.60 m, meeting the standards while ensuring maximized purification. Typha, an indigenous and prolific plant known for its purification abilities, was selected as the filtering agent. Concurrently, non-crushed gravel was chosen for its proven filtration capacity. This study is the result of a combination of scientific rigor and design expertise. It provides a holistic view of sanitation for Ndiebene Gandiol. The technical specifications and dimensions of the constructed wetland filter embody an approach that marries indepth analysis and practical application, all aimed at delivering an effective and long-lasting solution to the local sanitation challenges. By integrating precise scientific data with sanitation design expertise, this study delivers a holistic solution for Ndiebene Gandiol. The detailed dimensions and specifications of the constructed wetland filter reflect a methodology that combines meticulous analysis with practical adaptation, aiming to provide an effective and sustainable response to the challenges of rural and school sanitation in the northern region of Senegal.展开更多
We present a study of star-forming galaxies (SFGs) with pseudobulges (bulges with Sérsic index n<2) in a loca close major-merger galaxy pair sample (H-KPAIR).With data from new aperture photometries in the opt...We present a study of star-forming galaxies (SFGs) with pseudobulges (bulges with Sérsic index n<2) in a loca close major-merger galaxy pair sample (H-KPAIR).With data from new aperture photometries in the optical and near-infrared bands (aperture size of 7 kpc) and from the literature,we find that the mean Age of central stellar populations in Spirals with pseudobulges is consistent with that of disky galaxies and is nearly constant against the bulge-to-total ratio (B/T).Paired Spirals have a slightly lower fraction of pure disk galaxies (B/T≤0.1) than their counterparts in the control sample.Compared to SFGs with classical bulges,those with pseudobulges have a higher (>2σ) mean of specific star formation rate (sSFR) enhancement (sSFR_(enh)=0.33±0.07 versus sSFR_(enh)=0.12±0.06) and broader scatter (by~1 dex).The eight SFGs that have the highest sSFR_(enh)in the sample all have pseudobulges.A majority (69%) of paired SFGs with strong enhancement (having sSFR more than5 times the median of the control galaxies) have pseudobulges.The Spitzer data show that the pseudobulges in these galaxies are tightly linked to nuclear/circum-nuclear starbursts.Pseudobulge SFGs in S+S and in S+E pairs have significantly (>3σ) different sSFR enhancement,with the means of sSFR_(enh)=0.45±0.08 and-0.04±0.11respectively.We find a decrease in the sSFR enhancements with the density of the environment for SFGs with pseudobulges.Since a high fraction (5/11) of pseudobulge SFGs in S+E pairs are in rich groups/clusters (loca density N_(1Mpc)≥7),the dense environment might be the cause for their low s SFR_(enh).展开更多
Background: Conventional radiation therapy is a technique that uses ionizing radiation to destroy tumor cells. Along with surgery, chemotherapy, hormonotherapy and target therapy, it plays a crucial role in the manage...Background: Conventional radiation therapy is a technique that uses ionizing radiation to destroy tumor cells. Along with surgery, chemotherapy, hormonotherapy and target therapy, it plays a crucial role in the management of breast cancer by reducing its overall mortality and recurrences. Methods: We conducted a retrospective and descriptive study by using the records of patients treated in the radiotherapy department of the Douala General Hospital from January 2015 to December 2019. Data concerning radiation-induced toxicities were collected using a pre-established and pre-tested survey and transferred to the CTCAE Version 4.0 software. Data analysis was performed using SPSS version 20.0. Results: A total of 206 records were selected. The average age was 46.7 ± 8.2 years. The most represented histological type was invasive ductal carcinoma (n = 187, 90.7%). Multimodality treatment was used in every patient in our series with chemotherapy, surgery, and adjuvant radiation therapy (n = 88, 42.7%) been the most represented. More than half of the participants (n = 108, 52.4%) received a total dose >50 grays, only 89 (43.2%) received the classical fractionation of 2 grays/cession, and the average duration of radiation therapy was 36.8 ± 15.4 days. We encountered 155 (75.2%) side effects. There were more acute toxicities than late toxicities, at 115 (74.1%) versus 40 (25.8%). The main acute lesions were radiodermatitis (68.6%), breast pain (16.5%), radiation pneumonitis (12.2%), and acute pericarditis (2.6%). As late lesions, we identified radiodermatitis (52.5%), radiation pneumonitis (32.5%), and lymphoedema (15%). A total dose >50 grays [p 0.001, OR: 2.7 (1.58 - 4.9)], and conservative surgery [p = 0.04, OR: 2.3 (1.3 - 4.1)], seemed to increase the occurrence of early side effects on bivariate analysis. However, after multivariate logistic regression, only a total dose >50 grays [p = 0.005, OR: 2.1 (1.1 - 6.7)] remained a predictive factor associated to early side effects. We found no factors related to late side effect occurrences. Conclusion: The frequency of side effects of radiation therapy for breast cancer at the Douala General Hospital remains relatively high. Both early and late lesions remained present with early toxicities been the most common. Meticulous strategies along with an enhancement of both human and materials resources are paramount in order to reduce their frequency and morbidity.展开更多
Introduction: Head injuries constitute a public health problem in Cameroon and everywhere else in the world. They represent 23% of admissions to the Yaounde emergency center (CURY), which is a center exclusively dedic...Introduction: Head injuries constitute a public health problem in Cameroon and everywhere else in the world. They represent 23% of admissions to the Yaounde emergency center (CURY), which is a center exclusively dedicated, since 2014, to emergency care in Yaounde. In the management of trauma brain injuries at CURY, several are operated on. However, to date, no evaluation of these operated patients has yet been made. Goals: The objective of this study was to highlight the prognostic factors in patients operated for TBI at CURY. Methodology: We conducted a descriptive study whose data collection was done retrospectively over 2 years (01 January 2021 to 31 December 2022) at CURY. Data was collected from the registers of operative reports. Results: We enrolled 105 medical reports of patients who were victims of TBI operated on. The male gender predominated with a sex ratio of 3/1. The average age of the patients was 37.5 ± 18.83 years. Public road accidents were the leading cause of TBI in 75.2% of cases. The means of transport of the victims were mostly non-medical 97.1%. 45.7% of patients were admitted in less than 6 hours following injury. The initial clinical evaluation found 45.8% of patients with a Glasgow Coma Score (GCS) between [14, 15], and 13.2% of patients had a GCS 8. The indications for surgery were extradural hematoma (30%), followed by acute subdural hematoma (24%). The major complication was postoperative infection (25%). The mortality rate of the series was 7.9%. Poor prognostic factors were the depth of the coma on admission, advanced age and postoperative complications. Conclusion: The results of this study suggest that most patients operated on for TBI at CURY had a favorable outcome. The poor prognostic factors were the depth of the coma on admission, advanced age, postoperative complications and comorbidities.展开更多
The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and r...The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and red cultivars of X. sagittifolium, belonging to age intervals of 3 - 6, 6 - 9, and 9 - 12 months. Three harvest sites were chosen in the Central Region of Cameroon. In each site, soil from the rhizosphere and plant roots was collected in a randomized manner. In the field, the agronomic parameters were evaluated. The physicochemical characteristics of the soils, the mycorrhization index, and the morphological characterization of the mycorrhizal types of each site were carried out. The results obtained show that the agronomic growth parameters varied significantly using the Student Newman and Keuls Test depending on the harvest sites. The soils’ pH in all sites was acidic and ranged between 4.6 and 5.8. The Nkometou site has a loamy texture while the Olembe and Soa sites have loam-clay-sandy and loam-clay textures respectively. The highest mycorrhization frequencies appeared at the Nkometou site, with 75 and 87.33% of the white and red cultivars plant roots at 6 - 9 and 3 - 6 months. The relative abundance of AMF arbuscular mycorrhizal fungal spores in the rhizosphere of X. sagittifolium plants varied with age and cultivar. There were 673 spores between 9 - 12 months in Nkometou in the red cultivar. Six AMF genera were identified in all the different soils collected: Acaulospora sp., Funneliformis sp., Gigaspora sp., Glomus sp., Scutellospora sp., and Septoglomus sp. The genus Glomus sp. was the most present at all age intervals in both cultivars.展开更多
This work was a prospective transversal study over 6 (six) months from May 2 to December 31, 2017 at the Reference Health Center of Commune I and the Chérif la Confessional Health Center in Bamako. The aim was to...This work was a prospective transversal study over 6 (six) months from May 2 to December 31, 2017 at the Reference Health Center of Commune I and the Chérif la Confessional Health Center in Bamako. The aim was to study the knowledge, attitudes and behavioral practices linked to hemorrhoids in Commune I of the Bamako district, to evaluate the frequency of hemorrhoidal disease, to determine the knowledge, attitudes and behavioral practices linked to hemorrhoids among patients, their companions and traditional therapists in Commune I of the district of Bamako and the factors which influence the motivations and decisions to resort to medical-surgical care and traditional medicine in patients suffering from hemorrhoids in order to analyze the results of the management of hemorrhoidal disease at Cs Ref CI. We collected 36 patients with hemorrhoidal disease, 25 caregivers and 15 traditional hemorrhoidal disease therapists. The sex ratio was 1.25 for patients;6.5 for traditional therapists and 1.5 for accompanying people. The average age of the patients was 32.75 years;49 years for traditional therapists and 28.76 years for those accompanying them. 55.6% of patients claim to know about hemorrhoidal disease;100% of traditional therapists and 80% of accompanying people. The dietary factor of hemorrhoidal disease was mentioned by 90% of patients;66.7% of traditional therapists and 100% of caregivers. Most patients initially resorted to traditional treatment out of fear of surgery and its after-effects. The patients were treated medically and surgically.展开更多
文摘Plant biofertilization involves introducing compounds containing living mi-croorganisms into the coating medium to sustainably enhance plant production and soil health. This is a complex process that undergoes multiple stages of development before yielding a final product. The final biofertilizer is used by legumes-protein-rich crops in symbiosis with rhizobia to enable biological nitrogen fixation increasing natural soil fertility. This study aims to determine the optimal formulation of a rhizobial biofertilizer to improve the performance of soybean (Glycine max L. cv. Docko). To this end, soybean seeds obtained from IRAD were coated with different formulations derived from locally sourced materials. Palm kernel oil was used as an adhesive in one group, while corn powder served as an adhesive in another. The coated seeds were then sown in the field. The results indicate that the combination of pigeon pea powder + sugarcane molasses, with palm kernel oil as an adhesive, produced the best nodulation (nitrogen fixation). This formulation also led to significant improvements in growth (+350%) and total nitrogen content (+1100%) compared to the bacterial broth inoculum control (B0) (P ≤ 0.01). These findings represent a significant advancement in improving nitrogen-fixing bacterial inoculants and enhancing soil fertility for the sustainable cultivation of soybeans in this tropical soil.
文摘Background: In children, acute bacterial rhinosinusitis (ABRS) is often complicated by ophthalmological and/or neurological involvement. These complications should be known and recognized, as they require urgent treatment with intravenous antibiotics and close in-hospital monitoring. In this study, we aimed to identify the main risk factors associated with the development of complications in children aged 2 - 17 years with ABRS. Methods: We conducted a retrospective cohort study of patients with ABRS complications in a primary hospital. Participants were divided into two groups: the control group comprising patients without complications (Group 1, n = 82) and the study group comprising patients with complications requiring hospitalization (Group 2, n = 41). We assessed the sociodemographic, clinical, and imaging data of both groups. Using multivariate logistic regression, we assessed risk factors of ABRS complications. Results: No socio-demographic characteristics were associated with ABRS complications (p ≥ 0.05). Factors associated with complications were delay in consultation (t = 5.282;p Conclusions: Intracranial and extracranial complications of ABRS in children have become rare in our setting. These complications can be serious and potentially fatal. Risk factors of these complications are delays in consultation, the presence of ophthalmological signs, and more than one affected sinus. Controlling modifiable factors would improve the treatment success of ABRS complications in children.
文摘The prediction of the fracture plane orientation in fatigue is a scientific topic and remains relevant for every type of material. However, in this work, we compared the orientation of the fracture plane obtained experimentally through tests on specimens under multiaxial loading with that calculated by the variance method. In the statistical approach criteria, several methods have been developed but we have presented only one method, namely the variance method using the equivalent stress. She assumes that the fracture plane orientation is the one on which the variance of the equivalent stress is maximum. Three types of equivalent stress are defined for this method [1]: normal stress, shear stress and combined normal and shear stress. The results obtained were compared with experimental results for multiaxial cyclic stress states, and it emerges that the variance method for the case of combined loading is conservative as it gives a better prediction of the fracture plane.
文摘The waveguide which is at the center of our concerns in this work is a strongly flattened waveguide, that is to say characterized by a strong dispersion and in addition is strongly nonlinear. As this type of waveguide contains multiple dispersion coefficients according to the degrees of spatial variation within it, our work in this article is to see how these dispersions and nonlinearities each influence the wave or the signal that can propagate in the waveguide. Since the partial differential equation which governs the dynamics of propagation in such transmission medium presents several dispersion and nonlinear coefficients, we check how they contribute to the choices of the solutions that we want them to verify this nonlinear partial differential equation. This effectively requires an adequate choice of the form of solution to be constructed. Thus, this article is based on three main pillars, namely: first of all, making a good choice of the solution function to be constructed, secondly, determining the exact solutions and, if necessary, remodeling the main equation such that it is possible;then check the impact of the dispersion and nonlinear coefficients on the solutions. Finally, the reliability of the solutions obtained is tested by a study of the propagation. Another very important aspect is the use of notions of probability to select the predominant solutions.
文摘In this article, we study the impacts of nonlinearity and dispersion on signals likely to propagate in the context of the dynamics of four-wave mixing. Thus, we use an indirect resolution technique based on the use of the iB-function to first decouple the nonlinear partial differential equations that govern the propagation dynamics in this case, and subsequently solve them to propose some prototype solutions. These analytical solutions have been obtained;we check the impact of nonlinearity and dispersion. The interest of this work lies not only in the resolution of the partial differential equations that govern the dynamics of wave propagation in this case since these equations not at all easy to integrate analytically and their analytical solutions are very rare, in other words, we propose analytically the solutions of the nonlinear coupled partial differential equations which govern the dynamics of four-wave mixing in optical fibers. Beyond the physical interest of this work, there is also an appreciable mathematical interest.
文摘Introduction: Arteriovenous malformation is a rare pathology, often discovered accidentally in children. Generally, it presents as an intra-parenchymal hematoma following rupture of the affected vessels. The risk of rupture is linked to the volume of the malformation, its cortical location and venous drainage. In literature, few cases of rupture have been reported in cases of meningitis, but none are associated with a brain abscess. Objective: To report a case of an intraparenchymal hemorrhage due to rupture of an arteriovenous malformation with an associated brain abscess. Observation: The authors report the case of a 2-year-old child, admitted for impaired state of consciousness associated with a right hemiparesis and seizures in a febrile context. Clinical evaluation revealed a Blantyre score of 3, fever at 40˚C, divergent strabismus of the right eye, a right pyramidal syndrome and meningeal irritative syndrome. Cerebral CT scan revealed a left fronto-parietal intra-parenchymal hematoma and a right occipital ring-enhanced lesion, suggesting a brain abscess. An MRI suggested a probable rupture of an arteriovenous malformation resulting in the intra-parenchymal hematoma. Management consisted of craniotomy to evacuate the intra-parenchymal hematoma, antibiotic therapy with vancomycin and ceftriaxone at meningeal doses. Histopathological analysis of the intraoperative sample revealed an arteriovenous malformation. The postoperative course was marked by regression of hyperthermia, persistence of spasticity, irritability and clonic movement of the right lower limb. These were managed with baclofen, phenobarbital, and ergotherapy. We observed a regression of spasticity and improved motor skills in the right limbs. At 6 months follow-up, child could interact with his social environment despite aphasia, regression of spasticity and right hemiparesis. Conclusion: Rupture of arteriovenous malformations can be enhanced by neuro-meningeal infections and particularly brain abscesses. Cerebrovascular complications of these conditions mostly have unfavorable outcomes and neurological sequelae.
文摘Abortion is one of the leading causes of maternal death in Cameroon, despite numerous policies and strategies put in place to reduce it by 2030.This study aims to describe the epidemiologic aspects of abortions within hospitals in the city of Yaoundé in 2023. Methods: This was a descriptive cross-sectional study with prospective data collection in the maternity wards of the Yaoundé Gynaeco-Obstetric and Paediatric Hospital, and the Yaoundé Central Hospital for 7 months, from the 1st of November 2022 to the 31st of May 2023. The variables studied were demographic and clinical characteristics, means of recourse and post-abortion contraception. The frequency of abortions was calculated as the ratio of the number of abortions to the number of deliveries. The calculation of numbers and frequencies was used to describe the study population, and to highlight the sociodemographic and clinical characteristics of the patients recruited. Quantitative variables were expressed as mean ± standard deviation. Data were collected numerically and classified according to type, then analyzed using Epi-info version 7.2 software. Microsoft Office Excel 2013 was used to produce figures and tables. Results: During the study period, 169 patients were selected out of 1882 patients who had consulted for gynaecological emergencies;but only 164 of them accepted to participate. The frequency of abortions was 9.6% (169/1882). The age group of 25 to 29 years was the most represented, with 29.3% (48/164). They were mainly single 76.2% (125/164), and housewives 33.5% (55/164). The notion of previous abortion was found in 30.5% (50/164) of them. Approximately 19.5% of patients (32/164) reported to have conceived while using contraception, 56.2% of whom (18/32) used male condoms. At the time of admission to the emergency unit, the predominant symptom was bleeding in 70.7% of cases. The abortions were mainly spontaneous, in 75% of cases (123/164). In cases of induced abortions, 24.4% (10/41) of them took place after 14 weeks. Unexpected pregnancy was the main reason for termination in 46.3% of cases (19/41). Regarding induced abortion, 58.54% (24/41) of them resorted to voluntary medical termination. The mortality rate was 1.2%. The acceptability rate of a modern contraceptive method before discharge was 31.7%. Conclusion: Although frequent in our environment, data relating to abortion remain under-evaluated. Abortions occur mainly among young, single women, with a still very high proportion of induced abortions. The acceptability of post-abortion contraception remains poor. Prevention of unwanted pregnancies and risk factors is necessary to reduce the burden of abortions in low-income countries.
文摘From the ethyl acetate extract of the medicinal plant Graptophyllum glandulosum Turrill, five known compounds: Lupeol (1), Oleanolic acid (2), Chrysoeriol (3), N-methyl-isonicotinamide (4) and β-sitosterol 3-O-β-D-glucopyranoside (5) were isolated. In addition, oxidation reactions carried out on lupeol (1) yielded two semi-synthetic compounds, including a previously unreported: (20R)-formyloxy-29-nor-lupan-3-one (1b) and one other well-known Lupenone (1a). The structures of natural and semi-synthetic compounds were determined by analysis of 1D-(1H, 13C), 2D-(COSY, HSQC and HMBC) NMR data in conjunction with mass spectrometry (TOFESIMS and HR-TOFESIMS) and by comparison with the reported data. The evaluation of antimicrobial activities of substrate (1) as well as semi-synthetic derivatives (1a and 1b) using broth microdilution method showed that compound 1b was the most active (16 ≤ MIC ≤ 32 μg/mL) against Escherichia coli, Staphylococcus aureus and Candida albicans compared to the starting material 1 (16 ≤ MIC ≤ 64 μg/mL) and derivative 1a (32 ≤ MIC ≤ 64 μg/mL).
文摘The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the collection of wastewater samples. Their analysis revealed specific pollutant loads, including loads of BOD5 3.6966 kgO<sub>2</sub>/day and COD of 12.8775 kgO<sub>2</sub>/day, which were central to the design phase. Following a rigorous assessment of the existing sanitation infrastructure, constructed wetland (CWs) emerged as the most appropriate ecological solution. This system, valued for its ability to effectively remove contaminants, was tailored to the specific needs of the site. Consequently, the final design of the filter extends over 217.16 m<sup>2</sup>, divided into two cells of 108.58 m<sup>2</sup> each, with dimensions of 12.77 m in length and 8.5 m in width. The depth of the filtering medium is approximately 0.60 m, meeting the standards while ensuring maximized purification. Typha, an indigenous and prolific plant known for its purification abilities, was selected as the filtering agent. Concurrently, non-crushed gravel was chosen for its proven filtration capacity. This study is the result of a combination of scientific rigor and design expertise. It provides a holistic view of sanitation for Ndiebene Gandiol. The technical specifications and dimensions of the constructed wetland filter embody an approach that marries indepth analysis and practical application, all aimed at delivering an effective and long-lasting solution to the local sanitation challenges. By integrating precise scientific data with sanitation design expertise, this study delivers a holistic solution for Ndiebene Gandiol. The detailed dimensions and specifications of the constructed wetland filter reflect a methodology that combines meticulous analysis with practical adaptation, aiming to provide an effective and sustainable response to the challenges of rural and school sanitation in the northern region of Senegal.
基金supported by the National Natural Science Foundation of China(NSFC)No.11873055 and No.11933003sponsored(in part)by the Chinese Academy of Sciences(CAS)through a grant to the CAS South America Center for Astronomy(CASSACA)+4 种基金support from project PID2020-114414GB-100,financed by MCIN/AEI/10.13039/501100011033the Junta de Andaluciaía(Spain)grant FQM108support by the National Key R&D Program of China No.2017YFA0402600the National Natural Science Foundation of China(NSFC)grant Nos.11890692,12133008,and 12221003China Manned Space Project No.CMS-CSST2021-A04。
文摘We present a study of star-forming galaxies (SFGs) with pseudobulges (bulges with Sérsic index n<2) in a loca close major-merger galaxy pair sample (H-KPAIR).With data from new aperture photometries in the optical and near-infrared bands (aperture size of 7 kpc) and from the literature,we find that the mean Age of central stellar populations in Spirals with pseudobulges is consistent with that of disky galaxies and is nearly constant against the bulge-to-total ratio (B/T).Paired Spirals have a slightly lower fraction of pure disk galaxies (B/T≤0.1) than their counterparts in the control sample.Compared to SFGs with classical bulges,those with pseudobulges have a higher (>2σ) mean of specific star formation rate (sSFR) enhancement (sSFR_(enh)=0.33±0.07 versus sSFR_(enh)=0.12±0.06) and broader scatter (by~1 dex).The eight SFGs that have the highest sSFR_(enh)in the sample all have pseudobulges.A majority (69%) of paired SFGs with strong enhancement (having sSFR more than5 times the median of the control galaxies) have pseudobulges.The Spitzer data show that the pseudobulges in these galaxies are tightly linked to nuclear/circum-nuclear starbursts.Pseudobulge SFGs in S+S and in S+E pairs have significantly (>3σ) different sSFR enhancement,with the means of sSFR_(enh)=0.45±0.08 and-0.04±0.11respectively.We find a decrease in the sSFR enhancements with the density of the environment for SFGs with pseudobulges.Since a high fraction (5/11) of pseudobulge SFGs in S+E pairs are in rich groups/clusters (loca density N_(1Mpc)≥7),the dense environment might be the cause for their low s SFR_(enh).
文摘Background: Conventional radiation therapy is a technique that uses ionizing radiation to destroy tumor cells. Along with surgery, chemotherapy, hormonotherapy and target therapy, it plays a crucial role in the management of breast cancer by reducing its overall mortality and recurrences. Methods: We conducted a retrospective and descriptive study by using the records of patients treated in the radiotherapy department of the Douala General Hospital from January 2015 to December 2019. Data concerning radiation-induced toxicities were collected using a pre-established and pre-tested survey and transferred to the CTCAE Version 4.0 software. Data analysis was performed using SPSS version 20.0. Results: A total of 206 records were selected. The average age was 46.7 ± 8.2 years. The most represented histological type was invasive ductal carcinoma (n = 187, 90.7%). Multimodality treatment was used in every patient in our series with chemotherapy, surgery, and adjuvant radiation therapy (n = 88, 42.7%) been the most represented. More than half of the participants (n = 108, 52.4%) received a total dose >50 grays, only 89 (43.2%) received the classical fractionation of 2 grays/cession, and the average duration of radiation therapy was 36.8 ± 15.4 days. We encountered 155 (75.2%) side effects. There were more acute toxicities than late toxicities, at 115 (74.1%) versus 40 (25.8%). The main acute lesions were radiodermatitis (68.6%), breast pain (16.5%), radiation pneumonitis (12.2%), and acute pericarditis (2.6%). As late lesions, we identified radiodermatitis (52.5%), radiation pneumonitis (32.5%), and lymphoedema (15%). A total dose >50 grays [p 0.001, OR: 2.7 (1.58 - 4.9)], and conservative surgery [p = 0.04, OR: 2.3 (1.3 - 4.1)], seemed to increase the occurrence of early side effects on bivariate analysis. However, after multivariate logistic regression, only a total dose >50 grays [p = 0.005, OR: 2.1 (1.1 - 6.7)] remained a predictive factor associated to early side effects. We found no factors related to late side effect occurrences. Conclusion: The frequency of side effects of radiation therapy for breast cancer at the Douala General Hospital remains relatively high. Both early and late lesions remained present with early toxicities been the most common. Meticulous strategies along with an enhancement of both human and materials resources are paramount in order to reduce their frequency and morbidity.
文摘Introduction: Head injuries constitute a public health problem in Cameroon and everywhere else in the world. They represent 23% of admissions to the Yaounde emergency center (CURY), which is a center exclusively dedicated, since 2014, to emergency care in Yaounde. In the management of trauma brain injuries at CURY, several are operated on. However, to date, no evaluation of these operated patients has yet been made. Goals: The objective of this study was to highlight the prognostic factors in patients operated for TBI at CURY. Methodology: We conducted a descriptive study whose data collection was done retrospectively over 2 years (01 January 2021 to 31 December 2022) at CURY. Data was collected from the registers of operative reports. Results: We enrolled 105 medical reports of patients who were victims of TBI operated on. The male gender predominated with a sex ratio of 3/1. The average age of the patients was 37.5 ± 18.83 years. Public road accidents were the leading cause of TBI in 75.2% of cases. The means of transport of the victims were mostly non-medical 97.1%. 45.7% of patients were admitted in less than 6 hours following injury. The initial clinical evaluation found 45.8% of patients with a Glasgow Coma Score (GCS) between [14, 15], and 13.2% of patients had a GCS 8. The indications for surgery were extradural hematoma (30%), followed by acute subdural hematoma (24%). The major complication was postoperative infection (25%). The mortality rate of the series was 7.9%. Poor prognostic factors were the depth of the coma on admission, advanced age and postoperative complications. Conclusion: The results of this study suggest that most patients operated on for TBI at CURY had a favorable outcome. The poor prognostic factors were the depth of the coma on admission, advanced age, postoperative complications and comorbidities.
文摘The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and red cultivars of X. sagittifolium, belonging to age intervals of 3 - 6, 6 - 9, and 9 - 12 months. Three harvest sites were chosen in the Central Region of Cameroon. In each site, soil from the rhizosphere and plant roots was collected in a randomized manner. In the field, the agronomic parameters were evaluated. The physicochemical characteristics of the soils, the mycorrhization index, and the morphological characterization of the mycorrhizal types of each site were carried out. The results obtained show that the agronomic growth parameters varied significantly using the Student Newman and Keuls Test depending on the harvest sites. The soils’ pH in all sites was acidic and ranged between 4.6 and 5.8. The Nkometou site has a loamy texture while the Olembe and Soa sites have loam-clay-sandy and loam-clay textures respectively. The highest mycorrhization frequencies appeared at the Nkometou site, with 75 and 87.33% of the white and red cultivars plant roots at 6 - 9 and 3 - 6 months. The relative abundance of AMF arbuscular mycorrhizal fungal spores in the rhizosphere of X. sagittifolium plants varied with age and cultivar. There were 673 spores between 9 - 12 months in Nkometou in the red cultivar. Six AMF genera were identified in all the different soils collected: Acaulospora sp., Funneliformis sp., Gigaspora sp., Glomus sp., Scutellospora sp., and Septoglomus sp. The genus Glomus sp. was the most present at all age intervals in both cultivars.
文摘This work was a prospective transversal study over 6 (six) months from May 2 to December 31, 2017 at the Reference Health Center of Commune I and the Chérif la Confessional Health Center in Bamako. The aim was to study the knowledge, attitudes and behavioral practices linked to hemorrhoids in Commune I of the Bamako district, to evaluate the frequency of hemorrhoidal disease, to determine the knowledge, attitudes and behavioral practices linked to hemorrhoids among patients, their companions and traditional therapists in Commune I of the district of Bamako and the factors which influence the motivations and decisions to resort to medical-surgical care and traditional medicine in patients suffering from hemorrhoids in order to analyze the results of the management of hemorrhoidal disease at Cs Ref CI. We collected 36 patients with hemorrhoidal disease, 25 caregivers and 15 traditional hemorrhoidal disease therapists. The sex ratio was 1.25 for patients;6.5 for traditional therapists and 1.5 for accompanying people. The average age of the patients was 32.75 years;49 years for traditional therapists and 28.76 years for those accompanying them. 55.6% of patients claim to know about hemorrhoidal disease;100% of traditional therapists and 80% of accompanying people. The dietary factor of hemorrhoidal disease was mentioned by 90% of patients;66.7% of traditional therapists and 100% of caregivers. Most patients initially resorted to traditional treatment out of fear of surgery and its after-effects. The patients were treated medically and surgically.
