Spontaneous deformation during aging under stress in a copper-beryllium alloy

An anomalous phenomenon has been found in a Cu-Be alloy during an investigation of the aging behavior. A platelike testpiece of a cold-rolled Cu-Be alloy (Japanese Industrial Standard No. C1720) was held at 1073 K for 2 hours, followed by quenching to solutionize. The testpiece was set in a hand-made cantilever jig and aged by applying an external stress with a screw at the free end of the cantilever. The free end of the cantilever leaves the screw in 30 minutes and warps further, within 1 hour, during aging. The spontaneous warping deflection is closely related to the hardness change through aging and is dependent upon the elastic strain introduced initially by the external load. Transmission electron microscope (TEM) observation makes clear that matastable γ′ precipitates, which bring about the most effective hardening and shrinkage, are predominant at the compression side of the cantilever, while extremely fine Guinier—Preston (G—P) zones are observed at an early stage of aging and coarse γ-phase precipitates are observed at a prolonged aging time in the tension side. The spontaneous warping results from the difference of the precipitation sequence between the two sides.     

Acute myocardial infarction in a patient during dobutamine stress echocardiography

Combined chemotherapy/radiotherapy treatments appear to yield better results in locally advanced non-small-cell lung cancer (NSCLC) than radiotherapy alone. The optimal induction chemotherapy regimen remains to be established. In the present study, chemotherapy with cisplatin and vinorelbine was used prior to radical radiotherapy in Stage III-B NSCLC. Thirty-three patients were entered prospectively into a Phase II study. Treatment consisted of three cycles of chemotherapy with cisplatin 100 mg/m2 on day 1 and vinorelbine 30 mg/m2 on days 1 and 8, followed by thoracic radiotherapy (60 Gy). Twenty-two percent of the 33 patients had grade 3-4 leukopenia, and there were six episodes (in 4 patients) of neutropenia-associated fever. Gastrointestinal toxicity was generally moderate. Peripheral neuropathy was present in 42% of the patients, although in most of them it was slight. The main radiotherapy toxicity was esophagitis grade I-II. Evaluation of response after the third chemotherapy course showed an objective response in 16 patients (48%), whereas in three patients (9%) the disease progressed during therapy. The median survival of the entire group was 13 months. Cisplatin plus vinorelbine followed by radiotherapy is an effective schedule for patients with locally advanced non-small-cell lung cancer.     

Energy substrate metabolism during stress

Energy substrate metabolism during stress is characterized by increased REE (resting energy expenditure), hyperglycemia, hyperlactatemia and protein catabolism. This stress-induced hypermetabolic responses are closely related to increased secretion of neurohormonal and cytokine mediators. The insulin resistance hyperglycemia has been called "stress diabetes" or "surgical diabetes". Glucose disposal has been thought to be impaired in this condition. However, glucose uptake in most tissue is non-insulin mediated. Recent studies showed glucose uptake elevated in sepsis or TNF infusion. Insulin-regulatable glucose transporter (GLUT4) is present only in muscle, heart and adipose tissues. It was demonstrated that insulin binding to membrane receptors in these tissues was intact. This hyperglycemia in stress diabetes results from a postreceptor mechanism. Stress hyperlactatemia is thought to be caused by decreased pyruvate dehydrogenase activity rather than tissue hypoperfusion. Hyperlactatemia may promote gluconeogenesis. Glucose is a essential energy substrate in some tissues such as brain, erythrocyte and leukocyte. Hyperglycemia may be viewed as a beneficial response during stress.     

Perceived stress of nonhospitalized children during the hospitalization of a sibling

The purpose of this research was to examine nonhospitalized children's perceptions of the stress of the hospitalization of a sibling. The subjects were 45 nonhospitalized children (5-12 years of age), and their parents, who had a sibling hospitalized over 24 hours for a medical or surgical condition. The Child Drawing: Hospital (CD: H) was used to measure the perception of stress related to a sibling's hospitalization. The nonhospitalized children perceived the stress of hospitalization at a level of stress (anxiety) equal to the level of stress of hospitalized children and higher than children in a school setting found by previous investigators. Sex and age were not related to the degree of perceived stress (anxiety). The perception of stress varied significantly in relation to the type of sibling relationship, residence of the well sibling during the hospitalization, frequency of sibling visitation, and amount of parental behavior change as identified by the nonhospitalized children.     

The vegetal determinants required for the Spemann organizer move equatorially during the first cell cycle

Embryos with no dorsal axis were obtained when more than 15% of the egg surface was deleted from the vegetal pole of the early 1-cell embryo of Xenopus laevis. The timing of the deletion in the first cell cycle was critical: dorsal-deficient embryos were obtained when the deletion began before time 0.5 (50% of the first cell cycle) whereas normal dorsal axis usually formed when the deletion was done later than time 0.8. The axis deficiency could be restored by lithium treatment and the injection of vegetal but not animal cytoplasm. Bisection of the embryo at the 2-cell stage, which is known to restore the dorsal structures in the UV-ventralized embryos, had no effect on the vegetal-deleted embryos. These results show clearly that, in Xenopus, (1) the dorsal determinants (DDs) localized in the vegetal pole region at the onset of development are necessary for dorsal axis development and (2) the DDs move from the vegetal pole to a subequatorial region where they are incorporated into gastrulating cells to form the future organizing center. A model for the early axis formation process in Xenopus is proposed.