Miracle-dz/UniFAR-FTUs huggingface dataset:
‘Push’ versus ‘pull’ percutaneous endoscopic gastrostomy tube placement in patients with advanced head and neck cancer

Objectives/Hypothesis: Percutaneous endoscopic gastrostomy tube (PEG) placement by means of the “pull” method has been reported to result in a significantly higher complication rate when compared with “push” PEG placement. These findings have led to a renewed interest in the push, or Russell introducer, method of PEG placement at the authors' institution when PEG is required before definitive treatment of advanced head and neck cancer. The authors sought to determine whether the push method of PEG placement is associated with a lower incidence of complications in this patient population. Study Design: Nonrandomized, retrospective patient analysis. Methods: The medical records of all patients presenting to the Medical College of Georgia (Augusta, GA) who received a diagnosis of squamous cell carcinoma of the head and neck between 1999 to 2001 were retrospectively reviewed. Patients who required PEG placement as part of their treatment comprised the study population. Results: The push PEG technique was used in 29 patients, and the pull technique was used in 50 patients. There was a statistically significant difference in the complication rate between the two techniques. Patients who underwent placement by means of the pull technique had an overall complication rate of 30% (15 of 50) versus a 0% (0 of 29) complication rate in patients undergoing the push technique (P = .0006, Fisher's Exact test). Conclusion: The push PEG technique appears to have a significantly lower risk of complications compared with the pull technique in patients with advanced head and neck cancer. The authors recommend considering the use of the push method when PEG placement is required.
Waltzing route toward double-helix formation in cholesteric shells

Significance Droplets of chiral liquid crystals, or cholesterics, typically exhibit an intriguing radial defect which results from frustrations in the molecular order. This configuration shows a fascinating analogy to the Dirac monopole, a hypothetical magnetic charge, and plays a crucial role in the droplet optical properties, recently exploited to produce microlasers. Despite its evident interest, the nature of this disclination remains uncertain. We experimentally show, by studying spherical cholesteric shells, that it is composed of two line defects that wrap around each other on a double-helix structure. By tuning the system chirality, we can make this configuration dissociate into two independent stacks of disclination rings. The transition between configurations is reversible and entails an unexpected defect waltz dynamics. Liquid crystals, when confined to a spherical shell, offer fascinating possibilities for producing artificial mesoscopic atoms, which could then self-assemble into materials structured at a nanoscale, such as photonic crystals or metamaterials. The spherical curvature of the shell imposes topological constraints in the molecular ordering of the liquid crystal, resulting in the formation of defects. Controlling the number of defects, that is, the shell valency, and their positions, is a key success factor for the realization of those materials. Liquid crystals with helical cholesteric order offer a promising, yet unexplored way of controlling the shell defect configuration. In this paper, we study cholesteric shells with monovalent and bivalent defect configurations. By bringing together experiments and numerical simulations, we show that the defects appearing in these two configurations have a complex inner structure, as recently reported for simulated droplets. Bivalent shells possess two highly structured defects, which are composed of a number of smaller defect rings that pile up through the shell. Monovalent shells have a single radial defect, which is composed of two nonsingular defect lines that wind around each other in a double-helix structure. The stability of the bivalent configuration against the monovalent one is controlled by c = h/p, where h is the shell thickness and p the cholesteric helical pitch. By playing with the shell geometry, we can trigger the transition between the two configurations. This transition involves a fascinating waltz dynamics, where the two defects come closer while turning around each other.
Effects of extracellular changes on spontaneous heart rate of normoxia- and anoxia-acclimated turtles (Trachemys scripta)

SUMMARY Heart rate (fH) of the anoxia-tolerant freshwater turtle (Trachemys scripta) during prolonged anoxia exposure is 2.5- to 5-times lower than the normoxic rate, but whether alterations in blood composition that accompany prolonged anoxia contribute to this bradycardia is unknown. We examined how temperature acclimation, oxygen deprivation, acidosis, hyperkalemia, hypercalcemia and adrenaline affect chronotropy in the turtle myocardium. We monitored spontaneous contraction rates of right-atrial preparations obtained from 21°C- and 5°C-acclimated turtles that had been exposed to either normoxia or anoxia (6 h at 21°C; 2 weeks at 5°C). Sequential exposures to saline solutions were designed to mimic, in a step-wise manner, the shift from a normoxic to anoxic extracellular condition (for normoxia-acclimated preparations) or the reverse (for anoxia-acclimated preparations). Our results clearly show that prolonged anoxia exposure re-sets the intrinsic fH of turtles at both temperatures, with reductions in intrinsic fH in the range of 25%–53% compared with normoxia. This intrinsic change would contribute to the bradycardia observed with prolonged anoxia. Further, we found negative chronotropic effects of extracellular anoxia, acidosis and hyperkalemia, and positive chronotropic effects of hypercalcemia and adrenaline. The exact nature of these extracellular effects depended, however, on the acclimation temperature and the prior exposure of the animal to anoxia. With normoxia-acclimated preparations at 21°C, combined anoxia and acidosis (pH reduced from ∼7.8 to ∼7.2) significantly reduced spontaneous fH by 22% and subsequent exposure to hyperkalemia (3.5 mmol l–1K+) further decreased fH. These negative chronotropic effects were ameliorated by increasing the adrenaline concentration from the tonic level of 1 nmol l–1 to 60 nmol l–1. However, in anoxia-acclimated preparations at 21°C, anoxia alone inhibited fH (by ∼30%). This negative chronotropic effect was counteracted by both hypercalcemia (6 mmol l–1 Ca2+) and adrenaline (60 nmol l–1). At 5°C, only the combination of anoxia, acidosis (pH reduced from ∼8.0 to∼ 7.5) and hyperkalemia (3.5 mmol l–1 K+) significantly reduced spontaneous fH (by 23%) with preparations from normoxia-acclimated turtles. This negative chronotropic effect was fully reversed by hypercalcemia (10 mmol l–1 Ca2+). By contrast, spontaneous fH of anoxia-acclimated preparations at 5°C was not affected by any of the extracellular changes. We conclude that prior temperature and anoxia experiences are central to determining fH during prolonged anoxia in Trachemys scripta both as a result of the re-setting of pacemaker rhythm and through the potential influence of extracellular changes.
Spatial distribution of touristic flows in a gravity model in South America

Purpose This paper aims to investigate the determinants of international bilateral tourism demand in countries of Southern Common Market (specifically, Argentina, Brazil and Uruguay) and Chile. Design/methodology/approach In this study, an augmented gravity model is used to investigate the determinants of international bilateral tourism demand in countries of Southern Common Market. The novel aspect of the analysis is that three models of tourism are defined, depending on the spatial distribution of tourist arrivals and departures. An intra-regional model, an extra-regional model and a general model are estimated using a dynamic panel data model. Findings The results indicate that traditional gravity variables are significant in explaining bilateral inbound arrivals, but the characteristics and the behavior of the demand of tourism vary on whether the country belongs to the sub-regional bloc. Research limitations/implications The differences found in this paper might have some impacts on the desired design and direction of the touristic policies of each country. Originality/value This study analyzes the determinants of international tourism demand through different bilateral relationships, differentiating between intra- and extra-block tourisms.
On the question of nomenclature of homologous subdivisions of the inferior olivary complex.

The wide variety of terms, or other designations, that have been applied to the mammalian IO have been described above and are summarized in Tables I-IV. Although divergent in their general character there are some common threads that can be used to weave an acceptable and appropriate set of terms that can be applied to most, if not all, mammals studied to date. Concerning the MAO it is clear that there are six principal subdivisions of this part of IO (Table II A, II B). In addition to individual descriptive terms (such as 'ventral part') they have been designated as "subgroups", "cell groups", or "subnuclei" by various investigators. Since MAO, by its name (medial accessory nucleus) is already identified as a subdivision of IO, we suggest that the term 'subgroup' is appropriate to specify further subdivisions of this nucleus. With this in mind we suggest the following nomenclature for the MAO, subgroups, a, b, c (nucleus beta), and d (dorsal cap), the vlo, and dmcc. This is obviously a combination of styles currently in use yet when used together seem most appropriate for several reasons. First, the terms a-d have gained wide acceptance; acceptable equivalent terms for c and d are nucleus beta and dorsal cap, respectively. Second, this method method will accept present opinions concerning probable subdivisions of each subgroup, or future studies which may show that such further subparts exist. For example, such subdivisions can be designated as a and a1 (as is currently done in certain marsupials), b and b1 and so forth. Such an approach would also accommodate the suggestion that subgroup d (dorsal cap) in certain primates consists of two parts. It has been suggested that nucleus beta and subgroup c are separate entities in rat. However, the overwhelming opinion from studies on a variety of other forms is that these are separate terms for the same cell group. One could argue that nucleus beta in rat is subgroup c and what has been called c could be designated c1. Third, the terms vlo (ventrolateral outgrowth) and dmcc (dorsomedial cell column) have gained wide acceptance and, in our opinion, are preferable to other designations. To date no subdivisions of either of these cell groups have been proposed. In addition, the terms 'cell group g' and 'subnucleus g' have been used to describe parts of DAO and MAO, respectively. Consequently, continued use of this designation may confuse the terminology issue more than clarify it. (ABSTRACT TRUNCATED AT 400 WORDS)
Ballistic carrier transport in a quasi-two-dimensional nanoscale field effect transistor (FET)

The saturation velocity is found to be ballistic regardless of the device dimensions. This saturation velocity is limited by the intrinsic velocity appropriate to the 2D band structure of a MOSFET. The ballistic intrinsic velocity arises from the fact that randomly oriented velocity vectors in zero electric field are streamlined and become unidirectional. In the degenerate realm, the saturation velocity is shown to be the Fermi velocity that is independent of temperature but strongly dependent on carrier concentration. In the non-degenerate realm, the intrinsic velocity is the thermal velocity that depends only on the ambient temperature. The drain carrier velocity is revealed to be smaller than the saturation velocity due to the presence of a finite electric field at the drain. An excellent agreement of the models developed and applied to 80 nm MOSFET validates the physics behind ballistic carrier transport. The results presented will have profound influence in interpreting the data for a variety of low-dimensional nanoscale FET.
Antagonism of group III metabotropic glutamate receptors results in impairment of LTD but not LTP in the hippocampal CA1 region, and prevents long‐term spatial memory

Recently it has emerged that hippocampal long‐term depression (LTD) may play an important role in the acquisition and storage of spatial memories. This form of synaptic plasticity is tightly regulated by metabotropic glutamate receptors (mGluRs) that negatively couple to adenylyl cyclase. Activation of group III mGluRs is necessary for persistent hippocampal LTD, but is not required for depotentiation or long‐term potentiation (LTP) in the dentate gyrus in vivo. In the CA1 region antagonism of group III mGluRs prevents LTD in vivo. Effects on LTP in vivo are as yet unknown. We investigated the effects of group III mGluR antagonism on LTP and LTD at Schaffer collateral‐CA1 synapses, and on spatial learning in the eight‐arm radial maze. Daily application of the group III mGluR antagonist (R,S)‐α‐cyclopropyl‐4‐phosphonophenylglycine (CPPG) resulted in impairment of long‐term (reference) memory, with effects becoming apparent 4 days after training and drug treatment began. Short‐term (working) memory was unaffected throughout the 10‐day study. Application of CPPG prevented LTD, but not LTP, in the CA1 region. These data suggest that activation of group III mGluRs is required for the establishment of spatial long‐term memory. Their exclusive role in mediating hippocampal LTD provides correlational evidence for a role for LTD in the type of spatial learning studied.
Training affects the development of postural adjustments in sitting infants.

1. The present study addressed the question of whether daily balance training can affect the development of postural adjustments in sitting infants. 2. Postural responses during sitting on a moveable platform were assessed in twenty healthy infants at 5‐6, 7‐8 and 9‐10 months of age. Multiple surface EMGs and kinematics were recorded while the infants were exposed to slow and fast horizontal forward (Fw) and backward (Bw) displacements of the platform. After the first session the parents of nine infants trained their child's sitting balance daily. 3. At the youngest age, when none of the infants could sit independently, the muscle activation patterns were direction specific and showed a large variation. This variation decreased with increasing age, resulting in selection of the most complete responses. Training facilitated response selection both during Fw and Bw translations. This suggests a training effect on the first level of the central pattern generator (CPG) model of postural control. 4. Training also affected the development of response modulation during Fw translations. It accelerated the development of: (1) the ability to modulate EMG amplitude with respect to platform velocity and initial sitting position, (2) antagonist activity and (3) a distal onset of the response. These findings point to a training effect on the second level of the CPG model of postural adjustments.
A comparative study of the utilization of ether- and ester-linked phospholipid-containing liposomes by J774.E1 macrophage cell-line infected with Leishmania mexicana mexicana amastigotes.

The macrophage cell-line J774.E1 and Leishmania m. mexicana infection was used to investigate the uptake of liposomes, which differed in their bulk phospholipid: ester- or ether-analogue of phosphatydilcholine (PC). The receptor-mediated uptake of both species of liposomes, containing native or acetylated LDL as ligands was also evaluated. Uninfected and infected J774.E1 cell-line accumulated more ester- and ether-liposomes alone than mixed type (50:50, ester/ether). The utilization was significantly enhanced when both types of liposomes contained native LDL. The highest uptake was recorded for liposomes bearing acetylated LDL by infected J774.E1 cells. Accumulation of ester- and ether-liposomes with the same ligand was not markedly affected by different chemical nature of PC. Finally, ether-liposomes alone possessed certain activity against Leishmania m. mexicana amastigotes. The results presented here demonstrated the usefulness of ether-liposomes with specific ligands in site-specific delivery of antileishmanial compounds in vitro.
Molecular characterization of serotype G9 rotavirus strains from a global collection.

Between 1992 and 1998, serotype G9 human rotavirus (RV) strains have been detected in 10 countries, including Thailand, India, Brazil, Bangladesh, Malawi, Italy, France, the United States, the United Kingdom, and Australia, suggesting the possible emergence of the fifth common serotype worldwide. Unlike the previously characterized reference G9 strains (i.e., WI61 and F45), the recent G9 isolates had a variety of gene combinations, raising questions concerning their origin and evolution. To identify the progenitor strain and examine the on-going evolution of the recent G9 strains, we characterized by genetic and antigenic analyses 16 isolates obtained from children with diarrhea in India, Bangladesh, the United States, and Malawi. Specifically, we sequenced their VP7 and NSP4 genes and compared the nucleotide (nt) and deduced amino acid sequences with the reference G9 strains. To identify reassortment, we examined the products of five gene segments; VP4, VP7, and NSP4 genotypes (genes 4, 9, and 10); subgroups (gene 6); electropherotypes (gene 11); and the genogroup profiles of all of the recent G9 isolates. Sequence analysis of the VP7 gene indicated that the recent U.S. P[6],G9 strains were closely related to the Malawian G9 strains (>99% nt identity) but distinct from G9 strains of India ( approximately 97% nt identity), Bangladesh ( approximately 98% nt identity), and the reference strains ( approximately 97% nt identity). Phylogenetic analysis identified a single cluster for the U.S. P[6],G9 strains that may have common progenitors with Malawian P[6],G9 strains whereas separate lineages were defined for the Indian, Bangladeshi, and reference G9 strains. Northern hybridization results indicated that all 11 gene segments of the Malawian P[6],G9 strains hybridized with a probe derived from a U.S. strain of the same genotype and may have the same progenitor, different from the Indian G9 strains, whereas the Bangladesh strains may have evolved from the U.S. G9 progenitors. Overall, our findings suggest that much greater diversity among the newly identified G9 strains has been generated by reassortment between gene segments than through the accumulation of mutations in a single gene.
The impact of the extent of lymph-node dissection on biochemical relapse after radical prostatectomy in node-negative patients.

BACKGROUND The therapeutic role of pelvic lymph-node dissection (PLND) for prostate cancer (PCa) is still unclear. The aim of this study was to assess the impact of the number of lymph nodes (LN) retrieved at PLND during radical prostatectomy (RP) on biochemical relapse (BCR) in node-negative patients. PATIENTS AND METHODS From October 1995 to June 2009, 1510 consecutive PCa patients underwent RP at the University of Bologna hospital. A retrospective analysis was performed on 614 pT2-4N0 patients with a minimum follow-up of 12 months. All 614 patients underwent limited or extended PLND during RP. BCR-free survival was estimated using the Kaplan-Meier method. Cox regression was applied to analyse survivals rates. Patients were divided into two groups: group 1 (n=295) had 1 to 9 retrieved LNs and group 2 (n=319) had 10 or more retrieved. The parameters analysed were age, PSA, clinical and pathological Gleason score (GS), stage, margin status and adjuvant radiotherapy (ART). BCR was defined as PSA greater than 0.2 ng/ml. RESULTS Mean follow-up time was 62.5+/-39.7 months. Group 2 showed a significantly lower BCR than group 1 (p=0.019). LN group, PSA, clinical and pathological GS, pathological stage and ART all showed an independent and significant relationship with BCR using multivariate analysis. CONCLUSION In node-negative patients, a more extensive PLND affects BCR-free survival positively. A more extensive PLND may have a therapeutic role by removal of micrometastases.
Chiral Swiss rolls show a negative refractive index

Chiral Swiss rolls, consisting of a metal/dielectric laminate tape helically wound on an insulating mandrel, have been developed to form the basis of a highly chiral metamaterial. We have fabricated these elements using a custom-built machine, and have characterized them. We find that the permeability, permittivity, and chirality are all resonant in the region of 80 MHz. The chirality is so strong that it can be directly measured by observing the magnetic response to an applied electric field, and is larger than either the permeability or the permittivity. We have estimated the refractive indices from these data, and find both strong circular dichroism and a wide frequency range where the refractive index is negative.
Translocation of the Helicobacter pylori CagA protein in gastric epithelial cells by a type IV secretion apparatus

Helicobacter pylori is one of the most common bacterial pathogens, infecting about 50% of the world population. The presence of a pathogenicity island (PAI) in H. pylori has been associated with gastric disease. We present evidence that the H. pylori protein encoded by the cytotoxin‐associated gene A (cagA) is translocated and phosphorylated in infected epithelial cells. Two‐dimensional gel electrophoresis (2‐DE) of proteins isolated from infected AGS cells revealed H. pylori strain‐specific and time‐dependent tyrosine phosphorylation and dephosphorylation of several 125–135 kDa and 75–80 kDa proteins. Immunoblotting studies, matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS), cell fractionation and confocal microscopy demonstrated that one of the 125–135 kDa proteins represents the H. pylori CagA protein, which is translocated into the host cell membrane and the cytoplasm. Translocation of CagA was dependent on functional cagA gene and virulence (vir) genes of a type IV secretion apparatus composed of virB4, virB7, virB10, virB11 and virD4 encoded in the cag PAI of H. pylori. Our findings support the view that H. pylori actively translocates virulence determinants, including CagA, which could be involved in the development of a variety of gastric disease.
Assessing the impact of drug use on hospital costs.

OBJECTIVE To assess whether outpatient prescription drug utilization produces offsets in the cost of hospitalization for Medicare beneficiaries. DATA SOURCES/STUDY SETTING The study analyzed a sample (N=3,101) of community-dwelling fee-for-service U.S. Medicare beneficiaries drawn from the 1999 and 2000 Medicare Current Beneficiary Surveys. STUDY DESIGN Using a two-part model specification, we regressed any hospital admission (part 1: probit) and hospital spending by those with one or more admissions (part 2: nonlinear least squares regression) on drug use in a standard model with strong covariate controls and a residual inclusion instrumental variable (IV) model using an exogenous measure of drug coverage as the instrument. PRINCIPAL FINDINGS The covariate control model predicted that each additional prescription drug used (mean=30) raised hospital spending by $16 (p<.001). The residual inclusion IV model prediction was that each additional prescription fill reduced hospital spending by $104 (p<.001). CONCLUSIONS The findings indicate that drug use is associated with cost offsets in hospitalization among Medicare beneficiaries, once omitted variable bias is corrected using an IV technique appropriate for nonlinear applications.