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排序方式: 共有768条查询结果,搜索用时 31 毫秒
761.
Alessandro Ottaiano Mariachiara Santorsola Michele Caraglia Luisa Circelli Valerio Gigantino Gerardo Botti Guglielmo Nasti 《Translational oncology》2021,14(8)
Colorectal cancer (CRC) originates as consequence of multiple genetic alterations. Some of the involved genes have been extensively studied (APC, TP53, KRAS, SMAD4, PIK3CA, MMR genes) in highly heterogeneous and poly-metastatic cohorts. However, about 10% of metastatic CRC patients presents with an indolent oligo-metastatic disease differently from other patients with poly-metastatic and aggressive clinical course. Which are the genetic dynamics underlying the differences between oligo- and poly-metastatic CRC? The understanding of the genetic trajectories (primary→metastatic) of CRC, in patients selected to represent homogenous clinical models, is crucial to make genotype/phenotype correlations and to identify the molecular events pushing the disease towards an increasing malignant phenotype. This information is crucial to plan innovative therapeutic strategies aimed to reverse or inhibit these phenomena. In the present study, we review the genetic evolution of CRC with the intent to give a developmental perspective on the border line between oligo- and poly-metastatic diseases. 相似文献
762.
We propose a new generalization of the Drude model for describing the conductors in nanostructured form. The new feature that
appeared is the assumption of a collective mode at a finite frequency. This leads to the occurrence of anomalous charge transport.
With appropriate scattering times it is possible to mimic the infrared properties of oxides and poor conductors in the form
of nanoparticles and nanowires. The electron current in these cases reverses its direction before decaying to zero. Specific
examples considered are ZnO, TiO2, GaAs, Si, SWCN. The model also predicts that the current will have a damped oscillation in time, a possible new effect detectable
with femtosecond time resolved techniques. Results are presented for the velocity correlation functions, the mean square deviation
of position and the diffusion coefficient. 相似文献
763.
764.
A rhesus monkey was inoculated with rhesus cytomegalovirus. A leukocyte-associated herpes virus, unrelated to cytomegalovirus, was later isolated from the same monkey. Four years after the virus inoculation, the monkey developed a disseminated lymphoma. 相似文献
765.
Sabina Avosani Pietro Franceschi Marco Ciolli Vincenzo Verrastro Valerio Mazzoni 《Journal of Applied Entomology》2021,145(6):518-529
The meadow spittlebug Philaenus spumarius, vector of the bacterium Xylella fastidiosa, relies on vibrational communication to accomplish mating: the female calls to establish a duet with a male. A deeper knowledge of the species’ reproductive biology and behaviour would provide useful information for developing control techniques based on principles of ‘biotremology’, which studies the vibrational behaviour of animals. Playback tests were conducted on single females and male–female pairs of P. spumarius from June to October 2018, and the features of the recorded calling signals were analysed using a wavelet decomposition. Dissections were performed on females to evaluate the relationship between calling activity and ovarioles development. From August onwards, females started to emit calling signals and to develop ovarioles. Female calling activity, duration of their chirps and their responsiveness to mating increased as the season progressed, and they were correlated with ovarioles’ development and presence of mature eggs. Hence, the ovarian maturation represents a key factor in association with the development of the sexual behaviour of P. spumarius females. Conversely, males produced advertisement signals soon after adult eclosion in May, but these signals were not involved in the pair formation process. Mating was achieved only when males produced courtship signals in response to female calling signals and established with them vibrational duets starting from August. Here, we provide new information regarding the P. spumarius’ ethology and hypothesize that potential mating disruption techniques should consider the insect physiology and be applied when both sexes are responsive to mating signals. 相似文献
766.
767.
Filippo Drago Michele Grassi Carmela Valerio Germano Coppi Nunzio Lauria Giulio Cesare Nicotra Rocco Raffaele 《Peptides》1991,12(6):1309-1313
The behavioral activity of the thyrotropin-releasing hormone (TRH) analogue, L-6-ketopiperidine-2-carbonyl-leucyl-L-prolinamide (RGH 2202), has been studied in the rat. The number of errors in a radial maze test was reduced after acute intraperitoneal (IP) injection of RGH 2202 at the dose of 5 or 10 mg/kg. Grooming activity was increased with a lower dose, 1 mg/kg. Hypoxia-induced amnesia, as assessed with active and passive avoidance behavior tests, was reversed in rats treated with 5 or 10 mg/kg of the drug. The loss of learning and memory capacity shown by aged rats in the same behavioral tests was also reduced after injection of RGH 2202. In a test for sexual activity of male rats, the higher dose of the drug induced a facilitation of mounting and ejaculations, while smaller doses were ineffective. The rotorod test revealed a decreased number of falls in animals treated with 5 or 10 mg/kg of RGH 2202. In all behavioral tests, the same doses of natural thyrotropin-releasing hormone (TRH) were less effective, indicating that this analogue may be qualified as a potentially active drug in human pathologies. 相似文献
768.