1,635 research outputs found
Simple Formula for Nuclear Charge Radius
A new formula for the nuclear charge radius is proposed, dependent on the
mass number (A) and neutron excess (N-Z) in the nucleus. It is simple and it
reproduces all the experimentally available mean square radii and their
isotopic shifts of even--even nuclei much better than other frequently used
relations.Comment: The paper contains 7 pages in LateX and 6 figures (available upon
request) in postscript. Email: [email protected]
How to get a Large Natural-language System into a Personal Computer
The answer to the question of how to get a large natural-language system into a personal computer lies in the paging architecture of the system. The key is to use the input sentence, in conjunction with the lexicon and grammar table, to identify the minimal segments of both object code and data that must be brought into main memory. Once such a maximally paged architecture has been effectively implemented, it has wide ranging implications for process integration, networking and knowledge base distribution, and for the software engineering environment. The Natural Access System optimizes this architecture and exploits these implications
ASK is Transportable in Half a Dozen Ways
This paper is an informal discussion of the technical issues and solutions encountered in making the ASK. System transportable. A natural language system can be "transportable" in a number of ways, Although transportability to a new domain is most prominent, other ways are also important if the system is to have viability in the commercial marketplace.
"To transport" is a subcase of "to extend." To transport a system to a new domain is tantamount to starting with the system prior to adding any domain knowledge and extending it to incorporate the new domain. One may wish to add to a system that already has knowledge of one domain, the knowledge concerning a second domain, i.e., extend the system to cover this second domain. In the context of ASK, it has been natural to implement "extend", then achieve transportability as a special case.
We consider six ways in which the ASK System can be extended to include new capabilities;
--to a new domain
--to a new object type
--to access data from a foreign data base
--to a new natural language
--to a new programming language
--to a new computer famil
Effects of anti-triadin antibody on Ca2+ release from sarcoplasmic reticulum
AbstractThe monoclonal antibody, mAb GE 4.90, raised against triadin, a 95 kDa protein of sarcoplasmic reticulum (SR), inhibits the slow phase of Ca2+ release from SR following depolarization of the T-tubule moiety of the triad. The antibody has virtually no effect on the fast phase of depolarization-induced Ca2+ release nor on caffeine-induced Ca2+ release. Since the slow phase of depolarization-induced Ca2+ release is also inhibited by dihydropyridines (DHP), these results suggest that triadin may be involved in the functional coupling between the DHP receptor and the SR Ca2+ channel
The diagnostic value of dual-phase SPECT/CT scintigraphy based on transport kinetics of 99mTc-sestamibi confirmed with histopathological findings in patients with secondary hyperparathyroidism â practical consideration
BACKGROUND: Dual phase 99mTc-sestamibi SPECT/CT preoperative parathyroid scintigraphy (PPS) is seldom discussedin terms of the transport kinetics of the tracer.Objectives: To assess the relationship between the characteristic type of tracer transport in particular PPS and histopathologicalfindings in patients with secondary hyperparathyroidism (sHPT).MATERIAL AND METHODS: The study comprised 27 patients (13 females and 14 males) with sHPT. Based on tracer accumulationin early phase (EP) and delayed phase (DP), the following types of accumulation for PPS(+) lesions were identified: EP(â)/DP(+) (type I), EP(+)/DP(+) (type II), EP(+)/DP(â) (type III). EP(â)/DP(â) (type IV) lesions constituted PPS(â) group invisible inSPECT/CT. Overall, 69 lesions 59 PPS(+) and 10 PPS(â) were evaluated histopathologically.RESULTS: Among SPECT/CT PPS(+), types I, II and III occurred in 9 (15%), 49 (83%), and 1 (2%) lesions, respectively. Thefrequency of histopathological diagnosis of normal and abnormal (APG â adenoma or hyperplasia) parathyroid gland, as wellas non-parathyroid (thyroid, lymph nodes, or fat) lesions differed significantly between type I, II, and III lesions (p = 0.036).APG histopathological diagnosis was significantly more frequent in lesions with type II uptake than in lesions with type I uptake(76% vs. 33%, p = 0.0197). Type II lesions had significantly higher odds for histopathological diagnosis of APG or NPG thantype IV, PPS(â) lesions [odds ratio = 13.1 (95% CI: 2.75 to 63.27)].CONCLUSIONS: For SHP patients evaluated with SPECT/CT PPS accumulation type I is a weak premise for surgeon to findparathyroid pathology. Only persistent 99mTc-sestamibi accumulation in both phases - equivocal with accumulation type IIâ effectively differentiates parathyroid and non-parathyroid lesions as well as indicates with high probability the presence ofadenoma or hyperplasia. Type III consistent with washout pattern is rare in sHPT
Recommendations of the Polish Society of Gynecologists and Obstetricians regarding caesarean sections
In recent years, the worldwide percentage of deliveries by caesarean section has increased. However, this has only improved obstetric outcomes in low-income countries [1, 2]. Unfortunately, in Poland and other high-income countries, the rate of caesarean section, which is greater than 20%, is no longer associated with decreases in the perinatal mortality of mothers and their offspring. Currently in Poland, 43.85% of births are by caesarean section [3]. The increased number of caesarean sections may be associated with the development of perinatal medicine, and of diagnostics in particular, which can have an impact on the frequency of detecting foetal abnormalities. The results of randomised multicentre study carried out across various populations in the last two decades have indicated there is a greater risk to a child during vaginal delivery in cases of breech presentation [4]. Also, among women with one prior caesarean, planned elective caesarean section compared with planned vaginal birth was associated with a lower risk of fetal and infant death or serious infant outcome [5]. As a consequently, some national associations of obstetricians and gynecologists recommended the classification of pregnant women with these abnormalities for elective caesarean section. Epidemiological data from various populations indicate, however, that the main indications for caesarean section are still labour arrest and intrapartum fetal hypoxia [6, 7]
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Transcriptome Analysis of Proximal Tubular Cells (HK-2) Exposed to Urines of Type 1 Diabetes Patients at Risk of Early Progressive Renal Function Decline
Background: In patients with Type 1 Diabetes (T1D) who develop microalbuminuria, progressive decline in glomerular filtration rate (GFR) may be initiated by leakage into the urine of toxic proteins (txUPs). This study tested this hypothesis. Methods: After archiving baseline urine, we followed T1D patients with microalbuminuria for 8â12 years to distinguish those in whom GFR declined (Decliners) and those in whom it remained stable (Non-decliners). Human proximal tubular cells (HK-2 cells) were grown in serum-free medium enriched with pooled urines from Decliners or Non-decliners. We determined genome-wide expression profiles in extracted mRNA. Results: The two pooled urines induced differential expression of 312 genes. In terms of gene ontology, molecular functions of the 119 up-regulated genes were enriched for protein binding and peptidase inhibitor activities. Their biologic processes were enriched for defense response, responses to other organisms, regulation of cellular processes, or response to stress or stimulus, and programmed cell death. The 195 down-regulated genes were disproportionately represented in molecular functions of cation binding, hydrolase activity, and DNA binding. They were disproportionately represented in biological processes for regulation of metabolic processes, nucleic acid metabolic processes, cellular response to stress and macromolecule biosynthesis. The set of up-regulated genes in HK-2 cells overlaps significantly with sets of over-expressed genes in tubular and interstitial compartments of kidney biopsies from patients with advanced DN (33 genes in one study and 25 in the other compared with 10.3 expected by chance, p< and p<, respectively). The overlap included genes encoding chemokines and cytokines. Overlap of down-regulated genes was no more than expected by chance. Conclusions: Molecular processes in tubules and interstitium seen in advanced diabetic nephropathy can be induced in vitro by exposure to urine from patients with minimal microalbuminuria who subsequently developed progressive renal function decline, presumably due to putative txUPs
An in vivo model of anti-inflammatory activity of subdural dexamethasone following the spinal cord injury
Current therapies to limit the neural tissue destruction following the spinal cord injury are not effective. Our recent studies indicate that the injury to the white matter of the spinal cord results in a severe inflammatory response where macrophages phagocytize damaged myelin and the fluid-filled cavity of injury extends in size with concurrent and irreversible destruction of the surrounding neural tissue over several months. We previously established that a high dose of 4mg/rat of dexamethasone administered for 1 week via subdural infusion remarkably lowers the numbers of infiltrating macrophages leaving large amounts of un-phagocytized myelin debris and therefore inhibits the severity of inflammation and related tissue destruction. But this dose was potently toxic to the rats. In the present study the lower doses of dexamethasone, 0.125â2.0mg, were administered via the subdural infusion for 2 weeks after an epidural balloon crush of the mid-thoracic spinal cord. The spinal cord cross-sections were analyzed histologically. Levels of dexamethasone used in the current study had no systemic toxic effect and limited phagocytosis of myelin debris by macrophages in the lesion cavity. The subdural infusion with 0.125â2.0mg dexamethasone over 2 week period did not eliminate the inflammatory process indicating the need for a longer period of infusion to do so. However, this treatment has probably lead to inhibition of the tissue destruction by the severe, prolonged inflammatory process
Zebrafish Pou5f1-dependent transcriptional networks in temporal control of early development
Time-resolved transcriptome analysis of early pou5f1 mutant zebrafish embryos identified groups of developmental regulators, including SoxB1 genes, that depend on Pou5f1 activity, and a large cluster of differentiation genes which are prematurely expressed.Pou5f1 represses differentiation genes indirectly via activation of germlayer-specific transcriptional repressor genes, including her3, which may mediate in part Pou5f1-dependent repression of neural genes.A dynamic mathematical model is established for Pou5f1 and SoxB1 activity-dependent temporal
behaviour of downstream transcriptional regulatory networks. The model predicts that Pou5f1-dependent increase in SoxB1 activity significantly contributes to developmental timing in the early gastrula.Comparison to mouse Pou5f1/Oct4 reveals evolutionary conserved targets. We show that Pou5f1 developmental function is also conserved by demonstrating rescue of Pou5f1 mutant zebrafish embryos by mouse POU5F1/OCT4
Polymorphisms in the tyrosine kinase 2 and interferon regulatory factor 5 genes are associated with systemic lupus erythematosus
To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldSystemic lupus erythematosus (SLE) is a complex systemic autoimmune disease caused by both genetic and environmental factors. Genome scans in families with SLE point to multiple potential chromosomal regions that harbor SLE susceptibility genes, and association studies in different populations have suggested several susceptibility alleles for SLE. Increased production of type I interferon (IFN) and expression of IFN-inducible genes is commonly observed in SLE and may be pivotal in the molecular pathogenesis of the disease. We analyzed 44 single-nucleotide polymorphisms (SNPs) in 13 genes from the type I IFN pathway in 679 Swedish, Finnish, and Icelandic patients with SLE, in 798 unaffected family members, and in 438 unrelated control individuals for joint linkage and association with SLE. In two of the genes--the tyrosine kinase 2 (TYK2) and IFN regulatory factor 5 (IRF5) genes--we identified SNPs that displayed strong signals in joint analysis of linkage and association (unadjusted P<10(-7)) with SLE. TYK2 binds to the type I IFN receptor complex and IRF5 is a regulator of type I IFN gene expression. Thus, our results support a disease mechanism in SLE that involves key components of the type I IFN system
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