386 research outputs found
A relation between the short time variations of cosmic rays and geomagnetic field change
An event is reported of approx. 37 min periodicity in cosmic ray intensity observed at Akeno(38 deg 47 N, 138 deg 30 E. 900m above s.l., cutoff 10.4 GV) during 1300 approx. 1900 UT on April 25th, 1984, just a day before Forbush decrease of April 26th. This event seemed to be followed by the periodic variations of the geomagnetic field observed at Kakioka (36 deg 23 N, 140 deg 18 E). The regression coefficient between them was obtained approx. 0.07%/10nT. It is shown that in general the power spectral density of cosmic rays in the frequency of 0.0001 approx. 0.001Hz correlates positively with the fluctuations of geomagnetic field (Dst field) around approx. 1.2x0.0001Hz. From the analysis of 47 days data (April 14th to June 13th, 1984) the regression curve was obtained as y=0.275x sup 0.343 with the correlation coefficient of 0.48, where x and y mean Fourier components of Dst field summed over 1.04 approx. 1.39x0.001Hz and cosmic ray power spectral density averaged over 0.0001 approx. 0.001Hz
Analysis of Downhole Logs, Leg 57, Deep Sea Drilling Project
All sites drilled on Leg 57 were logged as weather
conditions permitted. The logging was done by the Singapore
office of Schlumberger, and because of short
notice the special logging tools required to pass through
the Challenger drill pipe were not available. The standard
centralizer, excentralizer, and caliper tools were
not appropriate, and those modified aboard ship were
not completely satisfactory. In addition, we suspected
that vertical motion from the ship's heave degraded the
quality of logs. Both the sonic and neutron density tools
were operated beyond their normal working ranges. Despite
these operational difficulties, the logs from different
runs in a hole, both repeat sections and runs with
different tools, show generally the same features. Over
intervals of 5 to 10 meters the field logs seem to be good
indicators of the physical character of the section penetrated
(Carson and Bruns, this volume).
The recovery of continuous core as well as logs differs
from normal industrial drilling practice, in which a
major purpose of logging is to establish lithology. Since
lithology is best established by direct examination, the
log analysis focused less on identifying a specific lithology
than on continuous measurement of in situ
physical properties, especially at Sites 438, 439, and 440,
where recovery was good. However, the logs were used
to establish the lithology of missing intervals, especially
at Site 441, where recovery was poor. Lithology and
physical properties aspects of the log analysis are covered
in the individual site chapters and in a comparative
analysis of laboratory measurements of physical properties
and logged physical parameters (Carson and Bruns,
this volume). In the present chapter we concentrate on
log precision, correlation of key horizons in seismic
records and core lithology, and on fracturing as indicated
by the logs. We do this by using the results of a
study of corrected logs and the derivative products from
computer programs developed by the Scientific Software
Corporation (SSC) and Technology Research Center
and of corrected logs from Schlumberger (available
from DSDP)
Epidemiological and diagnostic aspects of spontaneous miscarriage in the department of gynecology-obstetric of the university hospital of Treichville in Abidjan
Background: Describe the epidemiological and diagnostic of spontaneous aspects of early miscarriage in the department of the Gynecology Obsteric of Treichville University Teaching Hospital of  Treichville in Abidjan.Methods: A cross-sectional study was performed from January 2016 to March 2017 on patients received for an early miscarriage (gestational age less than 14 weeks of amenorrhea).Results: We recorded 337 cases of miscarriage and it shows that miscarriage was frequently estimated at 58 percent. Our patients had a average age of 32.9 years, 60.4 percent of them with primary education and 48 percent are housewives. The patients were paucigestes in 46 percent and the majority of them were nulliparous (62 percent). 6 percent with history of high blood pressure; diabetes (3 percent) and 31 percent of patients were HIV positive. Patients had pelvic pain at the admission in (55 percent). A miscarriage appears before 10 weeks of amenorrhea (76.1 percent) of cases. Ultrasound showed ovular debris (47 percent) of patients and (55.4 percent) were chromosomal abnormalities on anatomy-pathological examination.Conclusions: Spontaneous abortions are common and pathological examination is essential for diagnosis
Prioritizing otological surgery during the COVID-19 Pandemic
The initial cases of pulmonary infection with the novel corona virus SARS-CoV-2, causing COVID-19, occurred in Wuhan, Hubei Province, China in December 2019 and January 2020 (1). The spread through human-to-human transmission has led to a pandemic with disastrous consequences all over the world. The exponential rate of transmission and no existing vaccine has been a great challenge for all health care systems. A strategy to flatten the curve of transmission was put forward to adjust to the capacities of hospitals and particularly the intensive care units. Governments implemented isolation and social distancing upon societies either with laws or with strong recommendations
Management of tuberculosis of the uterine cervix in the University Hospital Center of Treichville
Genital tuberculosis is a rare entity which is classically presented with nonspecific signs posing diagnostic problems. We report the case of a young patient in genital activity, supported in our hospital for tuberculosis of the uterine cervix. She initially consulted for contact metrorrhagia and speculum examination had found an ulcerative budding cervix making suggest a cervical cancer. Finally, the histology of cervical biopsy confirmed the diagnosis of cervical tuberculosis and the patient was treated with anti-bacillary antibiotics. The evolution was favourable marked by declared healing after 6 months of treatment. The objective of this observation is to discuss the epidemiological, clinical and therapeutic characteristics of this affection
Simultaneous Two-Photon Absorption of the Thioguanosine Analogue 2âČ,3âČ,5âČ-Triâ<i>O</i>âacetyl-6,8-dithioguanosine with Its Potential Application to Photodynamic Therapy
2',3',5'-Tri-O-acetyl-6,8-dithioguanosine (taDTGuo) is an analogue of nucleosides and currently under investigation as a potential agent for photodynamic therapy (PDT). Excitation by simultaneous two-photon absorption of visible or near-infrared light would provide an efficient PDT for deep-seated tumors. The two-photon absorption spectrum of taDTGuo was obtained by optical-probing photoacoustic spectroscopy (OPPAS). A two-photon absorption band corresponding to the S5 â S0 transition was observed at 556 nm, and the two-photon absorption cross-section Ï(2) was determined to be 26 ± 3 GM, which was much larger than that of other nucleobases and nucleosides. Quantum chemical calculations suggested that the large Ï(2) value of taDTGuo was responsible for large transition dipole moments and small detuning energy resulting from the thiocarbonyl group at 6- and 8-positions. This is the first report on two-photon absorption spectra and cross-sections of thionucleoside analogues, which could be used to develop a more specific PDT for cancers in deep regions
Mesoporous stilbene-based lanthanide metal organic frameworks: synthesis, photoluminescence and radioluminescence characteristics
Mesoporous non-interpenetrating stilbene-based lanthanide metal organic frameworks exhibits photo and radioluminescence behavior.</p
Effect of Cu substitution on anion redox behaviour in P3-type sodium manganese oxides
This work was supported by the Faraday Institution (Grant No. FIRG018). The authors gratefully acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC), Grant Nos. EP/L017008/1, EP/R023751/1 and EP/T019298/1.Sodium layered oxides which display oxygen anion redox behaviour are considered promising positive electrodes for sodium-ion batteries because they offer increased specific capacities. However, they suffer from irreversible structural changes resulting in significant capacity loss and limited oxygen redox reversibility. Here the effect of Cu substitution on the electrochemical performance of P3-type sodium manganese oxide is examined by evaluating the structural and electronic structural evolution upon cycling, supported by density functional theory (DFT) calculations. Over the voltage range 1.8â3.8 V vs. Na/Na+, where the redox reactions of the transition metal ions contribute entirely towards the charge compensation mechanism, stable cycling performance is maintained, showing a capacity retention of 90% of the initial discharge capacity of 166 mA h gâ1 after 40 cycles at 10 mA gâ1. Over an extended voltage range of 1.8â4.3 V vs. Na/Na+, oxygen anion redox is invoked, with a voltage hysteresis of 110 mV and a greater initial discharge capacity of 195 mA h gâ1 at 10 mA gâ1 is reached. Ex-situ powder x-ray diffraction patterns reveal distortion of the P3 structure to P'3 after charge to 4.3 V, and then transformation to O'3 upon discharge to 1.8 V, which contributes towards the capacity fade observed between the voltage range 1.8â4.3 V. DFT with projected density of states calculations reveal a strong covalency between the copper and oxygen atoms which facilitate both the cationic and anionic redox reactions in P3-type Na0.67Mn0.9Cu0.1O2.Publisher PDFPeer reviewe
Illegals abortions and utero-digestives lesions: retrospective study of 12 cases in the Department of Gynecology and Obstetrics at the Treichville teaching hospital (Abidjan, Cote Dâivoire)
Background: Traumatic intestinal digestive damage after abortion by endo-uterine manoeuvres are not uncommon. The purpose of this study is to describe the diagnostic, therapeutic and prognostic aspects of these lesions.Methods: This is a retrospective study of 3 years on patients with a uterine lesion associated with a digestive traumatic injury during illegal abortions endo-uterine manoeuvres.Results: 12 patients with a median age of 23, 9 are included. The clinical manifestations are not specific: impairment of the general condition 33.3%; hyperthermia 83.3% (or 10 cases); digestive disorders such as diarrhoea 25%, vomiting 33.3%; abdominal pain 100%; occlusive syndrome 16.7%; acute abdominal syndrome 75%. The seat of traumatic injuries is variable. The lesions were for hail alone in 4 cases (33.3%), colon alone for 2 cases (16.7%), rectum 1 case and epiploon 2 cases. In these 3 cases, the lesions were associated, sitting on both the hail and the colon at a time. All these lesions were associated with uterine perforation of variable siege. The therapeutic management consisted of a small bowel resection with ileostomy in 5 cases or 41.7%; colon resection with colostomy 3 cases or 25%; suture lesions after beveling beiges 5 cases either 41, 7 in 2 cases, we performed haemostasis on the bleeding epiploon. Treatment of the uterine lesion was conservative 75% of the time. The evolution on the 10 patients was favorable, 83.3%. Two patients died early in the operative course after septic shock.Conclusions: The digestive lesions are a factor aggravating the prognosis of post-abortion uterine manoeuvres. Their management must be rapid and requires close collaboration between the digestive surgeon and the Gynecologist
Enhanced cycling stability in the anion redox material P3-type Zn-substituted sodium manganese oxide
Funding: Faraday Institution (Grant Number(s): FIRG018), Diamond Light Source (Grant Number(s): SP14239), Engineering and Physical Sciences Research Council (Grant Number(s): EP/L017008/1, EP/R023751/1, EP/T019298/1), SPRing8 (Grant Number(s): 2021A1425).Sodium layered oxides showing oxygen redox activity are promising positive electrodes for sodiumâion batteries (SIBs). However, structural degradation typically results in limited reversibility of the oxygen redox activity. Herein, the effect of Znâdoping on the electrochemical properties of P3-type sodium manganese oxide, synthesised under air and oxygen is investigated for the first time. AirâNa 0.67 Mn 0.9 Zn 0.1 O 2 and OxyâNa 0.67 Mn 0.9 Zn 0.1 O 2 exhibit stable cycling performance between 1.8 and 3.8 V, each maintaining 96% of their initial capacity after 30 cycles, where Mn 3+ /Mn 4+ redox dominates. Increasing the voltage range to 1.8â4.3 V activates oxygen redox. For the material synthesised under air, oxygen redox activity is based on Zn, with limited reversibility. The additional transition metal vacancies in the material synthesised under oxygen result in enhanced oxygen redox reversibility with small voltage hysteresis. These results may assist the development of highâcapacity and structurally stable oxygen redoxâbased materials for SIBs.Publisher PDFPeer reviewe
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