Applications of a super element model for non-linear analysis of stiffened box structures

Numerical investigations are carried out to verify the new super element model developed in Reference 1 for non-linear analysis of stiffened box structures. The results presented here are obtained from a variety of examples which are chosen to illustrate the accuracy and convergence of the model in various applications. Good agreement is obtained for most of the problems considered and the present formulation is found to be accurate and economical for preliminary engineering design.     

Cost-effectiveness of preoperative localization studies in primary hyperparathyroid disease

OBJECTIVE: To evaluate the effect of preoperative localization studies on the surgical management of patients with primary hyperparathyroid disease (PHPT). SUMMARY BACKGROUND DATA: Reported cure rates of initial surgical exploration for PHPT are close to 95%. Preoperative localization studies are frequently obtained to improve surgical success and decrease operative time. METHODS: Initial cervical exploration was performed in 113 patients with PHPT from 1981 to 1993. Twenty-four patients (21%) had surgery without preoperative localization studies. The remaining 89 patients (79%) had 132 noninvasive preoperative localization studies. Success of the localization studies in tumor localization, pathologic findings, postoperative serum calcium levels, and operative times were compared. Patient costs of the studies were calculated. RESULTS: Disease was identified during operation in 23 of 24 patients (96%) having cervical exploration without preoperative localization studies, and they had normal calcium levels after surgery. Eighty-seven of 89 patients (98%) having preoperative localization studies were surgically cured. The highest sensitivity rate (60%) and highest positive predictive value (79%) of the localization studies were found with thallium-technetium scintiscanning. Average cost of the localization studies was $901 per patient. Combination studies were obtained in 32 patients at an average cost of $1,314 per patient without improving sensitivity. Mean operating time did not differ for localized and nonlocalized patients. CONCLUSIONS: Preoperative localization studies did not improve parathyroid localization or cure rate and did not substantially shorten operating time in initial cervical exploration for PHPT. The economic burden of routine preoperative localization studies in these patients is not justified.     

Synaptic-like microvesicles of neuroendocrine cells originate from a novel compartment that is continuous with the plasma membrane and devoid of transferrin receptor

We have characterized the compartment from which synaptic-like microvesicles (SLMVs), the neuroendocrine counterpart of neuronal synaptic vesicles, originate. For this purpose we have exploited the previous observation that newly synthesized synaptophysin, a membrane marker of synaptic vesicles and SLMVs, is delivered to the latter organelles via the plasma membrane and an internal compartment. Specifically, synaptophysin was labeled by cell surface biotinylation of unstimulated PC12 cells at 18 degrees C, a condition which blocked the appearance of biotinylated synaptophysin in SLMVs and in which there appeared to be no significant exocytosis of SLMVs. The majority of synaptophysin labeled at 18 degrees C with the membrane-impermeant, cleavable sulfo-NHS-SS-biotin was still accessible to extracellularly added MesNa, a 150-D membrane-impermeant thiol-reducing agent, but not to the 68,000-D protein avidin. The SLMVs generated upon reversal of the temperature to 37 degrees C originated exclusively from the membranes containing the MesNa-accessible rather than the MesNa-protected population of synaptophysin molecules. Biogenesis of SLMVs from MesNa-accessible membranes was also observed after a short (2 min) biotinylation of synaptophysin at 37 degrees C followed by chase. In contrast to synaptophysin, transferrin receptor biotinylated at 18 degrees or 37 degrees C became rapidly inaccessible to MesNa. Immunofluorescence and immunogold electron microscopy of PC12 cells revealed, in addition to the previously described perinuclear endosome in which synaptophysin and transferrin receptor are colocalized, a sub-plasmalemmal tubulocisternal membrane system distinct from caveolin-positive caveolae that contained synaptophysin but little, if any, transferrin receptor. The latter synaptophysin was selectively visualized upon digitonin permeabilization and quantitatively extracted, despite paraformaldehyde fixation, by Triton X-100. Synaptophysin biotinylated at 18 degrees C was present in these subplasmalemmal membranes. We conclude that SLMVs originate from a novel compartment that is connected to the plasma membrane via a narrow membrane continuity and lacks transferrin receptor.     

Stereotactic radiosurgery of malignant and benign intracranial lesions utilizing a patient rotator

The objective of this survey was to demonstrate whether a primary care track internal medicine residency program emphasizing community-based health care of the urban sick poor trains physicians who will continue to practice in general internal medicine or similar fields. Thirty-five primary care residents (100% of graduates) who trained from 1976 through 1993 in the Adult Primary Care Track of the Internal Medicine Residency Program at St. Vincent's Hospital, New York were used as participants.     

Moral reasoning and moral concerns: An alternative to Gilligan's gender based hypothesis.

Studied the differences in moral orientation in terms of gender specific modes of reasoning, in 2 experiments. In Exp 1, 32 Ss (aged 24–55 yrs) were read the "Heinz dilemma," and asked 3 questions regarding it. Deliberative and justificatory strategies were identified on the basis of the presence or absence of the higher level knowledge structures. In Exp 2, 40 undergraduates were presented with "Michael and Kohlberg Heinz dilemma," followed by a set of relevant questions. Male Ss preferred to apply a norm or rule in their solutions, while females rejected the application of a norm and sought alternative solutions. This was replicated in Exp 2, but the pattern was reversed with female Ss preferring to apply a norm. Males were divided in their use of either strategy indicating that although, genders differed in their judgments as to which norms or rules to apply; once adopted, norms and rules were used in similar ways. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Swords to plowshares: Shock wave applications to advanced lithography

xtreme ltra iolet ithography (EUVL) seeks to apply radiation in a wavelength region centered near 13 nm to produce microcircuits having feature sizes 0.1 micron or less. A critical requirement for the commercial application of this technology is the development of an economical, compact source of this radiation which is suitable for lithographic applications. A good candidate is a laser-plasma source, which is generated by the interaction of an intermediate intensity laser pulse (up to 10¹² W/cm²) with a metallic target. While such a source has radiative characteristics which satisfy the needs of an EUVL source, the debris generated during the laser-target interaction strikes at the economy of the source. Here, we review the use of concepts and computer modeling, originally developed for hypervelocity impact analysis, to study this problem.     

The role of DnaJ-like proteins in glucocorticoid receptor.hsp90 heterocomplex assembly by the reconstituted hsp90.p60.hsp70 foldosome complex

The glucocorticoid receptor (GR) is recovered from hormone-free cells in a heterocomplex with the molecular chaperone hsp90, which is required to produce the proper folding state for steroid binding. GR.hsp90 heterocomplexes are formed by a multiprotein system that appears to exist in all eukaryotic cells. Recently, we have reconstituted a receptor.hsp90 heterocomplex assembly system with purified rabbit hsp90 and hsp70 and bacterially expressed human p23 and p60. We have shown that hsp90, p60, and hsp70 form an hsp90.p60. hsp70 complex that converts the GR from a non-steroid binding to a steroid binding form (Dittmar, K. D., and Pratt, W. B. (1997) J. Biol. Chem. 272, 13047-13054). The resulting GR.hsp90 heterocomplex rapidly disassembles unless p23 is present to bind to the ATP-dependent conformation of hsp90 and stabilize its association with the receptor (Dittmar, K. D., Demady, D. R., Stancato, L. F., Krishna, P., and Pratt, W. B. (1997) J. Biol. Chem. 272, 21213-21220). In the current work, we show that the purified rabbit hsp70 utilized in prior studies is contaminated with a small amount of the rabbit DnaJ homolog hsp40. Elimination of the hsp40 from the purified GR.hsp90 assembly system reduces assembly activity, and the activity is restored by addition of the purified yeast DnaJ homolog YDJ-1. hsp40 is a component of the hsp90.p60.hsp70 foldosome complex isolated from reticulocyte lysate with antibody against p60. Under conditions that promote binding of p23 to hsp90 (elevated temperature, ATP, Nonidet P-40, molybdate), a five-membered (p23. hsp90.p60.hsp70.hsp40) complex of chaperone proteins is formed in reticulocyte lysate or from purified proteins. The hsp40-free, purified assembly system has a modest level of assembly activity that is maximally potentiated by YDJ-1 when it is present at about one-twentieth the concentration of hsp70. Although hsp40 is not in the final GR.hsp90 heterocomplex isolated from L cell cytosol, it is in the GR.hsp90 heterocomplex assembled in reticulocyte lysate. We conclude that hsp40 is a component of the multiprotein hsp90-based chaperone system where it potentiates GR.hsp90 heterocomplex assembly.     

Inhibitory effects of centrally administered somatostatin on the adrenal zona glomerulosa in male rats

Segmental zoster paresis (SZP) is the focal, asymmetrical neurogenic weakness which may occur in a limb affected by cutaneous zoster. We have summarized the features of this syndrome, based on a retrospective review of 8 personal and 96 published cases. Limb SZP becomes apparent in at least 3-5% of patients with cutaneous zoster, who are usually over the age of sixty and weak proximally (C5,6,7 or L2,3,4 innervated muscles). Functional motor recovery occurs in about 75% of cases, generally by 1-2 years. Limb weakness is probably due to a lesion of the ventral nerve root, in close proximity to the initiating dorsal ganglionitis. The electrodiagnostic findings, scarce in the literature, typically consist of absent compound sensory nerve action potentials in the involved limb, with less frequent reduction or loss of compound muscle action potentials. Fibrillations and positive sharp waves become detectable within 1-4 months in limb and related paraspinal muscles, decreasing or disappearing later. In addition to this radiculopathy, peripheral nerves may also occasionally become involved, manifest as mononeuropathies of the median, ulnar, long thoracic, recurrent laryngeal, and phrenic nerves. The zoster infection or consequent inflammatory response appears able to affect motor axons distally as well as proximally.