6,535 research outputs found
Characterization of Hyperbolic Cylinders in a Lorentzian Space Form
We give a characterization of the n-dimensional (n ≥ 3) hyperbolic cylinders in a Lorentzian space form. We show that the hyperbolic cylinders are the only complete space-like hypersurfaces in an (n + 1)-dimensional Lorentzian space form M₁ⁿ⁺¹(c) with non-zero constant mean curvature H whose two distinct principal curvatures λ and μ satisfy inf(λ - μ)² > 0 for c ≤ 0 or inf(λ - μ)² > 0, H² ≥ c, for c > 0, where λ is of multiplicity n - 1 and μ of multiplicity 1 and λ 0 при c ≤ 0 или inf(λ - μ)² > 0, H² ≥ c, при c > 0, где λ имеет порядок n - 1, а μ порядок 1 и λ < μ
Extra-hepatic fascioliasis with peritoneal malignancy tumor feature
Fascioliasis is a zoonose parasitic disease
caused by Fasciola hepatica and Fasciola gigantica and is
widespread in most regions of the world. Ectopic fascioliasis
usually caused by juvenile Fasciola spp., but in
recent years a few cases of tissue-embedded ova have been
reported from different endemic areas. A 79-year-old Iranian
man resident in Eird-e-Mousa village from Ardabil
Province, north-west of Iran, complained with abdominal
pain, nausea, and intestinal obstruction symptoms referred
to Ardabil Fatemi hospital. In laparotomy multiple intestinal
masses with peritoneal seeding resembling of a
malignant lesion were seen. After appendectomy and peritoneal
mass biopsy with numerous intraperitoneal adenopathy,
paraffin embedded blocks were prepared from
each tissues. A blood sample was taken from the patient
5 months later for serological diagnosis. Histopathological
examination of sections showed fibrofatty stroma with
dense mixed inflammatory cells infiltration and fibrosis in
peritoneal masses. Large numbers of ova of Fasciola spp.
were noted with typical circumscribed granulomas. Despite
of anti-fasciola treatment, IHA test for detecting anti F.
hepatica antibodies was positive 5 months after surgery
with a titer of 1/128. Due to multiple clinical manifestation
of extra-hepatic fascioliasis, its differential diagnosis from
intraperitoneal tumors or other similar diseases should be
considered
Effects of L-Arginine on Seizure Behavior and Expression of GFAP in Kainic Acid-Treated Rats
Rats i.p. injected once with 10 mg/kg kainic acid exhibited clear seizure behavior (“wet-dog
shakes,” rearing on the hindlimbs, and bilateral clonus). Pretreatment with L-arginine (L-Arg
twice a day for 5 days) significantly decreased these manifestations. The medium dose of
L-Arg (40 mg/kg) was found to be close to optimum; 10 and 160 mg/kg L-Arg provided much
smaller positive effects. In KA-treated rats, a much higher density of GFAP positive astrocytes was found in the hilus of the dorsal hippocampus, while 40 mg/kg L-Arg+KA-treated
rats demonstrated noticeably weaker GFAP overexpression. The results of Western blotting
analysis were fully comparable with those obtained in the immunostaining experiments.Поведінка щурів, яким внутрішньоочеревинно ін’єкували
10 мг/кг каїнової кислоти (КК), характеризувалася вираженими проявами судом, „струшуваннями мокрого собаки”,
вставанням на задні кінцівки та білатеральним клонусом.
Попередні введення L-аргініну (L-Aрг) двічі на день протягом п’яти днів забезпечували істотне зменшення інтенсивності таких проявів. Було виявлено, що доза L-Aрг 40 мг/кг
є близькою до оптимальної; дози 10 та 160 мг/кг справляли
менш виражену позитивну дію. У щурів, яким уводили КК,
у хілусі дорсального гіпокампа спостерігалася більш висока щільність астроцитів, імунопозитивних щодо гліального фібрилярного кислого білка (GFAР), у той час як у щурів, котрим уводили КК сумісно із 40 мг/кг L-Арг, експресія
GFAP була виражена в помітно меншій мірі. Результати досліджень з використанням Вестерн-блотингу були повністю
співставними з даними, отриманими в експериментах з імуногістологічним міченням
Architecture of Pol II(G) and molecular mechanism of transcription regulation by Gdown1.
Tight binding of Gdown1 represses RNA polymerase II (Pol II) function in a manner that is reversed by Mediator, but the structural basis of these processes is unclear. Although Gdown1 is intrinsically disordered, its Pol II interacting domains were localized and shown to occlude transcription factor IIF (TFIIF) and transcription factor IIB (TFIIB) binding by perfect positioning on their Pol II interaction sites. Robust binding of Gdown1 to Pol II is established by cooperative interactions of a strong Pol II binding region and two weaker binding modulatory regions, thus providing a mechanism both for tight Pol II binding and transcription inhibition and for its reversal. In support of a physiological function for Gdown1 in transcription repression, Gdown1 co-localizes with Pol II in transcriptionally silent nuclei of early Drosophila embryos but re-localizes to the cytoplasm during zygotic genome activation. Our study reveals a self-inactivation through Gdown1 binding as a unique mode of repression in Pol II function
A New Remote Guided Method for Supervised Web-Based Cognitive Testing to Ensure High Quality Data
Background. The global COVID-19 pandemic has triggered a fundamental reexamination of how human psychological research can be conducted both safely and robustly in a new era of digital working and physical distancing. Online web-based testing has risen to the fore as a promising solution for rapid mass collection of cognitive data without requiring human contact. However, a long-standing debate exists over the data quality and validity of web-based studies. Here, we examine the opportunities and challenges afforded by the societal shift toward web-based testing, highlight an urgent need to establish a standard data quality assurance framework for online studies, and develop and validate a new supervised online testing methodology, remote guided testing (RGT).
Methods. A total of 85 healthy young adults were tested on 10 cognitive tasks assessing executive functioning (flexibility, memory and inhibition) and learning. Tasks were administered either face-to-face in the laboratory (N=41) or online using remote guided testing (N=44), delivered using identical web-based platforms (CANTAB, Inquisit and i-ABC). Data quality was assessed using detailed trial-level measures (missed trials, outlying and excluded responses, response times), as well as overall task performance measures.
Results. The results indicated that, across all measures of data quality and performance, RGT data was statistically-equivalent to data collected in person in the lab. Moreover, RGT participants out-performed the lab group on measured verbal intelligence, which could reflect test environment differences, including possible effects of mask-wearing on communication.
Conclusions. These data suggest that the RGT methodology could help to ameliorate concerns regarding online data quality and - particularly for studies involving high-risk or rare cohorts - offer an alternative for collecting high-quality human cognitive data without requiring in-person physical attendance.Biotechnology and Biological Sciences Research Council (H012508 and BB/P021255/1).
Wellcome Trust (205067/Z/16/Z)
A retrospective analysis of second-line chemotherapy in patients with advanced gastric cancer
<p>Abstract</p> <p>Background</p> <p>Because treatment of advanced gastric cancer (AGC) patients after failure with first-line chemotherapy remains controversial, we performed this retrospective analysis based on the data obtained from 1455 patients registered in a first-line treatment cohort with respect to receiving or not receiving subsequent chemotherapy.</p> <p>Methods</p> <p>The decision for administering second-line chemotherapy was, in most cases, at the discretion of the physician. Seven-hundred twenty-five (50%) received second-line chemotherapy after first-line failure. Univariate and multivariate analyses were performed on the recognized baseline parameters for survival.</p> <p>Results</p> <p>At the time of initiating second-line chemotherapy, the patients' median age was 56 years (range, 22 to 86) and 139 (19%) had an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or more. Seven (1%) complete and 108 (15%) partial responses to second-line chemotherapy were observed for an overall response rate of 16% (95% confidence interval [CI], 13 to 19%). The median progression-free and overall survivals, calculated from the start of second-line chemotherapy, were 2.9 months (95% CI, 2.6 to 3.3) and 6.7 months (95% CI, 5.8 to 7.5), respectively. Multivariate analysis revealed that low baseline hemoglobin level (hazard ratio [HR], 0.74; 95% CI 0.61–0.90) and a poor performance status (HR, 0.66; 95% CI, 0.52–0.83) were independent negative prognostic factors for overall survival.</p> <p>Conclusion</p> <p>Performance status, along with baseline hemoglobin level, could be used to identify the subgroup of patients most likely to benefit from second-line chemotherapy for AGC.</p
EGFR Gene Overexpression Retained in an Invasive Xenograft Model by Solid Orthotopic Transplantation of Human Glioblastoma Multiforme Into Nude Mice
Orthotopic xenograft animal model from human glioblastoma multiforme (GBM) cell lines often do not recapitulate an extremely important aspect of invasive growth and epidermal growth factor receptor (EGFR) gene overexpression of human GBM. We developed an orthotopic xenograft model by solid transplantation of human GBM into the brain of nude mouse. The orthotopic xenografts sharing the same histopathological features with their original human GBMs were highly invasive and retained the overexpression of EGFR gene. The murine orthotopic GBM models constitute a valuable in vivo system for preclinical studies to test novel therapies for human GBM
On tree amplitudes with gluons coupled to gravitons
In this paper, we study the tree amplitudes with gluons coupled to gravitons.
We first study the relations among the mixed amplitudes. With BCFW on-shell
recursion relation, we will show the color-order reversed relation,
-decoupling relation and KK relation hold for tree amplitudes with gluons
coupled to gravitons. We then study the disk relation which expresses mixed
amplitudes by pure gluon amplitudes. More specifically we will prove the disk
relation for mixed amplitudes with gluons coupled to one graviton. Using the
disk relation and the properties of pure gluon amplitudes, the color-order
reversed relation, -decoupling relation and KK relation for mixed
amplitudes can also be proved. Finally, we give some brief discussions on
BCJ-like relation for mixed amplitudes.Comment: 33pages,no figur
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