Search

Here, we demonstrate the enhancement of the transverse magneto-optical Kerr effect (TMOKE) signal, due to surface plasmon resonance in the Otto configuration, where the low index dielectric has a variable thickness. This constitutes a demonstration that, in principle, a separation of the magnetic sample from the plasmonic device and the modulation of the plasmon resonance with an enhancement of the MOKE signal is possible. We have achieved this by using air as a low index dielectric where the evanescent wave extends, preceding to excitation of surface plasmons. The magnetic sample under consideration is a thin layer of cobalt coated by an ultrathin silver layer, on a silicon substrate (Ag/Co/Si). The sample is brought close enough to the prism/air interface, allowing surface plasmon excitation in the air/Ag interface. This leads to an increase of the TMOKE signal up to ~ 2 ‰ with respect to the incident light. This is about 7 times the traditional MOKE signal in the absence of plasmons. This is comparable with previous works using the Kretschmann-Raether configuration. Furthermore, the fact that the plasmon field generated at the metal-air interface substitutes the laser light used in traditional MOKE allows new functionalities such as controlling the penetration depth of the plasmonic field into the sample. This should find applications in magnetometry and related technology. [ABSTRACT FROM AUTHOR]

A non-conventional modification of exfoliated few-layer graphene (FLG) with different arynes under microwave (MW) irradiation and solvent-free conditions is reported. The described approach allows reaching fast, efficient and mild covalent functionalization of FLG. [ABSTRACT FROM AUTHOR]

------------------------- The online version of the original article can be found at https://doi.org/10.1007/s11468-022-01762-0 ------------------------- Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The online version of the original article can be found at https://doi.org/10.1007/s11468-022-01762-0 B Correction to: Plasmonics (2023) 18:719-726 b https://doi.org/10.1007/s11468-022-01762-0 The original version of this article unfortunately contained a mistake. I am the third author of this article, and my affiliation institution has recently required me to use the full name of my university (Universidad Distrital Francisco José de Caldas) and to avoid the use of the acronym FJC for Francisco José de Caldas. [Extracted from the article]

The expansion of the invasive rainbow trout Oncorhynchus mykiss into the thermal headwaters of Valcheta Stream (Patagonia, Argentina) and new predation records on the endangered endemic naked characin Gymnocharacinus bergii are presented here. These findings are discussed in relation to the contemporary evolution and thermal refuges hypothesis. This study has immediate implications for the conservation of G. bergii. [ABSTRACT FROM AUTHOR]

Background We previously showed that abdominal distension in patients with functional gut disorders is due to a paradoxical diaphragmatic contraction without major increment in intraabdominal volume. Our aim was to characterize the pattern of gas retention and the abdomino-thoracic mechanics associated with abdominal distension in patients with intestinal dysmotility. Methods In 15 patients with manometrically proven intestinal dysmotility, two abdominal CT scans were performed: one during basal conditions and other during an episode of severe abdominal distension. In 15 gender- and age-matched healthy controls, a basal scan was performed. Key Results In basal conditions, patients exhibited more abdominal gas than healthy subjects, particularly in the small bowel, and the volume significantly increased during an episode of distension. During episodes of abdominal distension, the increase in abdominal content was associated with increased girth and antero-posterior abdominal diameter, as well as a cephalic displacement of the diaphragm, which reduced the height of the lung. The consequent reduction in the air volume of the lung was attenuated by an increase in the antero-posterior diameter of the chest. Conclusions & Inferences Abdominal distension in patients with severe intestinal dysfunction is related to marked pooling of gut contents, particularly in the small bowel. This increase in content is accommodated within the abdominal cavity by a global and coordinated abdomino-phreno-thoracic response, involving an accommodative ascent of the diaphragm and a compensatory expansion of the chest wall. [ABSTRACT FROM AUTHOR]

We give a geometrical description of the action of the parity operator ( $$\hat{P}$$) on non-relativistic spin 1/2 Pauli spinors in terms of bundle theory. The relevant bundle, $$SU(2)\odot Z_2\to O(3)$$, is a non-trivial extension of the universal covering group $$\hbox{\it SU}(2)\to \hbox{\it SO}(3). \hat{P}$$ is the non-relativistic limit of the corresponding Dirac matrix operator $${\cal P}=i\gamma_0$$ and obeys $$\hat{P}^2=-1$$. From the direct product of O(3)$ by $$Z_2$$, naturally induced by the structure of the Galilean group, we identify, in its double cover, the time-reversal operator ( $$\hat{T}$$) acting on spinors, and its product with $$\hat{P}. \hat{P}$$ and $$\hat{T}$$ generate the group $$Z_4 \times Z_2$$. As in the case of parity, $$\hat{T}$$ is the non-relativistic limit of the corresponding Dirac matrix operator $${\cal T}=\gamma^3 \gamma^1$$, and obeys $$\hat{T}^2=-1$$. [ABSTRACT FROM AUTHOR]

Purpose: Prevention of parastomal hernia represents an important aim when a permanent stoma is necessary. The objective of this work is to assess whether implantation of a prophylactic prosthetic mesh during laparoscopic abdominoperineal resection contributed to reduce the incidence of parastomal hernia. Methods: Rectal cancer patients undergoing elective laparoscopic abdominoperineal resection with permanent colostomy were randomized to placement of a large-pore lightweight mesh in the intraperitoneal/onlay position by the laparoscopic approach (study group) or to the control group (no mesh). Parastomal hernia was defined radiologically by a CT scan performed after 12 months of surgery. The usefulness of subcutaneous fat thickness measured by CT to discriminate patients at risk of parastomal hernia was assessed by ROC curve analysis. Results: Thirty-six patients were randomized, 19 to the mesh group and 17 to the control group. Parastomal hernia was detected in 50 % of patients in the mesh group and in 93.8 % of patients in the control group ( P = 0.008). The AUC for thickness of the subcutaneous abdominal was 0.819 ( P = 0.004) and the optimal threshold 23 mm. Subcutaneous fat thickness ≥23 mm was a significant predictor of parastomal hernia (odds ratio 15.7, P = 0.010), whereas insertion of a mesh was a protective factor (odds ratio 0.06, P = 0.031). Conclusions: Use of prophylactic large-pore lightweight mesh in the intraperitoneal/onlay position by a purely laparoscopic approach reduced the incidence of parastomal hernia formation. Subcutaneous fat thickness ≥23 mm measured by CT was an independent predictor of parastomal hernia. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To assess the long-term evolution and predictive factors of type B intramural hematoma (IMH). Material and methods: 34 patients (33 men), mean age: 67 years (47–87) diagnosed with type B IMH by computed tomography (CT) and followed up clinically and by CT yearly. Mean follow-up was 5.9 years (2–13 years). Two evolution patterns were considered: (a) regression and (b) progression. Clinical and imaging variables were analyzed for assessing their predictor values. Results: Evolution at one year was to regression in 56% and to progression in 44% of cases. There were no association among age, sex, other aortic abnormalities, presence of atherosclerotic disease or blood pressure, initial maximum aortic diameter, indexed maximum aortic diameter, IMH thickness or length, presence or absence of mediastinal hematoma and the evolution of type B IMH. Ten patients had small aortic ulcers in the acute phase. The presence of ulcers was related with progression of IMH. No differences were observed in evolution between the control at first year and the last control. Conclusions: The presence of small ulcers is a strong predictor of evolution in acute type B IMH. In addition, the regression group remains completely stable after the first year of evolution. [Copyright &y& Elsevier]

Background: Mild cognitive deficits have been reported in essential tremor (ET). However, these cognitive deficits have been assessed in cross-sectional rather than longitudinal analyses. Objective: To determine whether decline in cognitive test scores occurs at a faster rate in ET cases than controls. Methods: In a population-based study of older people (≥ 65 years) in central Spain (Neurological Disorders in Central Spain, NEDICES), non-demented ET cases and controls were followed prospectively. Participants with baseline or incident Parkinson’s disease or dementia were excluded as were participants who developed incident ET. At baseline (1994–1995) and at follow-up (1997–1998), a 37-item version of the mini-mental state examination (37-MMSE) was administered. Results: A total of 2319 participants (72.4 ± 5.8 years) included 135 prevalent ET cases and 2184 controls. At baseline, the mean 37-MMSE in cases was 28.8 ± 5.8 vs. 30.2 ± 4.8 in controls ( P = 0.02). During the 3-year follow-up period, the 37-MMSE declined by 0.70 ± 3.2 points in cases vs. 0.11 ± 3.8 points in controls ( P = 0.03). In analyses that adjusted for age, education, and other potential confounders, the case–control difference remained robust. Discussion: In this population-based, prospective study of non-demented elders, baseline cognitive test scores were lower in ET cases than controls; moreover, during the 3-year follow-up period, these scores declined at a rate that was seven-times faster in ET cases. This study provides evidence that cognitive deficits in ET are not static, and they appear to be progressing at a faster rate than in elders without this disease. [ABSTRACT FROM AUTHOR]

Background: Many investigators have observed mild cognitive deficits in essential tremor (ET), yet the functional significance of these deficits is unclear. Also, there are very few data in which functional activity in ET has been divided into cognitively based activities (remembering appointments) versus motor-based activities (writing cheques).Objective: The authors (1) compared functional level in ET cases versus controls, assessing functional activities that are cognitively based and those that are dependent upon both motor and cognitive factors, and (2) determined whether lower mini mental status test scores in ET cases have a functional correlate.Methods: In a population-based study of people > or = 65 years in central Spain (NEDICES), a 37-item version of the Mini-Mental State Examination (37-MMSE) and an 11-item version of the Pfeffer Functional Activities Questionnaire (FAQ) were administered to non-demented ET cases and controls.Results: The FAQ was 55.5% higher (ie, lower function) in 208 cases than 3616 controls (2.8+/-4.8 vs 1.8+/-4.2, p<0.001). Cases reported more difficulty (ie, higher FAQ scores) with FAQ items that were cognitive measures as well as FAQ items that were cognitive-motor in nature. In cases, a lower 37-MMSE was associated with more difficulty on both cognitively based and cognitive-motor-based FAQ items (p<0.001).Discussion: In this large, population-based study, ET cases reported more functional difficulty than controls, and this functional difficulty was present in both cognitive and cognitive-motor domains. Lower cognitive test scores were associated with more reported functional difficulty, indicating that lower cognitive test scores in ET, rather than being inconsequential, have a clear clinical-functional correlate. [ABSTRACT FROM AUTHOR]

The water supply for human consumption in the Chaco-Pampean region in Argentina is restricted by the low quality of groundwater due to elevated concentrations of arsenic and other trace elements. Previous studies indicated a complex concurrence of factors and processes that are believed responsible to control the distribution of arsenic in groundwater. For a better understanding of the origin of trace elements in the Pampean aquifer, flow-through experiments with loess and calcrete samples representative of the sediments that constitute the aquifer were carried out in continuous flow reactors. The aqueous solutions were collected and the concentrations of SiO 2 (aq), Ca2+, SO 4 2−, Na+, Cl−, F− and trace elements (Ba, Sr, V, and As) were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), high performance liquid chromatography (HPLC) and capillary electrophoresis. The experiments showed differences in the release rate of elements to the solution according to the type of sediment. The highest concentrations of V, Ba, and As were measured in experiments conducted with loess, and these elements were released quickly to the solution in the first minute of the test. In the case of loess, V and As are suggested to be adsorbed on the solid particles surface. Conversely, the experiments conducted with calcrete showed a lower but continuous release of those elements. This last result may indicate that the trace elements were coprecipitated in the calcite. In addition, it was demonstrated that F did not come from the dissolution of minerals such as fluorapatite, but both desorption from solid surface and dissolution from calcite minerals account for the release of F. This study support that both dissolution and adsorption-desorption processes can control the mobility of trace elements, with an emphasis on the role of calcrete in the retention and the mobilization of trace elements in the Pampean aquifer. Unlabelled Image • The origin of As, F and other pollutants in groundwater is still misunderstood. • Consumption of water with high content of As is a major threat for human health. • Time-resolved experiments were used to study elemental release in water. • As, V, Ba, Sr are probably coprecipitated with calcite and F adsorbed on calcite. • The mobility of pollutants in the Pampean Aquifer is controlled by calcrete. [ABSTRACT FROM AUTHOR]

In this work, we assessed the occupancy of two native amphibian species of the Valcheta stream in the Somuncura Plateau, northern Patagonia: the Valcheta frog, Pleurodema somuncurense and the Argentine common toad, Rhinella arenarum. We hypothesized that the occupancy of both amphibian species will be shaped by the presence of trout; we also expected a decline in occupancy assuming that the new predator in the system will affect native amphibian populations. Between December 2014 and March 2015, we conducted surveys in 148 sites along the headwaters of Valcheta stream. We modelled the occupancy by including the presence of trout, the temperature of water and the coverage of rocks and vegetation as site-habitat covariates. Models including trout were among the best ranked for both amphibian species. The presence of trout reduced the occupancy of both species and the magnitude of this reduction was much higher in the Valcheta frog than in the Argentine common toad. Overall, our results are of great relevance for land managers considering that the Valcheta frog is among the only three IUCN Critically Endangered amphibians in Argentina. [ABSTRACT FROM AUTHOR]

Background Gut content may be determinant in the generation of digestive symptoms, particularly in patients with impaired gut function and hypersensitivity. Since the relation of intraluminal gas to symptoms is only partial, we hypothesized that non-gaseous component may play a decisive role. Methods Abdominal computed tomography scans were evaluated in healthy subjects during fasting and after a meal ( n = 15) and in patients with functional gut disorders during basal conditions (when they were feeling well) and during an episode of abdominal distension ( n = 15). Colonic content and distribution were measured by an original analysis program. Key Results In healthy subjects both gaseous (87 ± 24 mL) and non-gaseous colonic content (714 ± 34 mL) were uniformly distributed along the colon. In the early postprandial period gas volume increased (by 46 ± 23 mL), but non-gaseous content did not, although a partial caudad displacement from the descending to the pelvic colon was observed. No differences in colonic content were detected between patients and healthy subjects. Symptoms were associated with discrete increments in gas volume. However, no consistent differences in non-gaseous content were detected in patients between asymptomatic periods and during episodes of abdominal distension. Conclusions & Inferences In patients with functional gut disorders, abdominal distension is not related to changes in non-gaseous colonic content. Hence, other factors, such as intestinal hypersensitivity and poor tolerance of small increases in luminal gas may be involved. [ABSTRACT FROM AUTHOR]

Background The precise relation of intestinal gas to symptoms, particularly abdominal bloating and distension remains incompletely elucidated. Our aim was to define the normal values of intestinal gas volume and distribution and to identify abnormalities in relation to functional-type symptoms. Methods Abdominal computed tomography scans were evaluated in healthy subjects ( n = 37) and in patients in three conditions: basal (when they were feeling well; n = 88), during an episode of abdominal distension ( n = 82) and after a challenge diet ( n = 24). Intestinal gas content and distribution were measured by an original analysis program. Identification of patients outside the normal range was performed by machine learning techniques (one-class classifier). Results are expressed as median ( IQR) or mean ± SE, as appropriate. Key Results In healthy subjects the gut contained 95 (71, 141) mL gas distributed along the entire lumen. No differences were detected between patients studied under asymptomatic basal conditions and healthy subjects. However, either during a spontaneous bloating episode or once challenged with a flatulogenic diet, luminal gas was found to be increased and/or abnormally distributed in about one-fourth of the patients. These patients detected outside the normal range by the classifier exhibited a significantly greater number of abnormal features than those within the normal range (3.7 ± 0.4 vs 0.4 ± 0.1; p < 0.001). Conclusions & Inferences The analysis of a large cohort of subjects using original techniques provides unique and heretofore unavailable information on the volume and distribution of intestinal gas in normal conditions and in relation to functional gastrointestinal symptoms. [ABSTRACT FROM AUTHOR]

Abstract: Neurons are highly polarized cells, composed of one axon and several branching dendrites. One important issue in neurobiology is to understand the molecular factors that determine the neuron to develop polarized structures. A particularly early event, in neurons still lacking a discernible axon, is the segregation of IGF-1 (Insulin like Growth Factor-1) receptors in one neurite. This receptor can be activated by insulin in bulk, but, it is not known if changes of insulin organization as a monomolecular film may affect neuron polarization. To this end, in this work we developed solid-supported Langmuir–Blodgett films of insulin with different surface packing density. Hyppocampal pyramidal neurons, in early stage of differentiation, were cultured onto those substrates and polarization was studied after 24h by confocal microscopy. Also we used surface reflection interference contrast microscopy and confocal microscopy to study attachment patterns and morphology of growth cones. We observed that insulin films packed at 14mN/m induced polarization in a similar manner to high insulin concentration in bulk, but insulin packed at 44mN/m did not induce polarization. Our results provide novel evidence that the neuron polarization through IGF-1 receptor activation can be selectively modulated by the lateral packing of insulin organized as a monomolecular surface for cell growth. [Copyright &y& Elsevier]

Background Cross-sectional imaging techniques, including ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI), are increasingly used for evaluation of Crohn's disease (CD). Aim To perform an assessment of the diagnostic accuracy of cross-sectional imaging techniques for diagnosis of CD, evaluation of disease extension and activity and diagnosis of complications, and to provide recommendations for their optimal use. Methods Relevant publications were identified by literature search and selected based on predefined quality parameters, including a prospective design, sample size and reference standard. A total of 68 publications were chosen. Results Ultrasonography is an accurate technique for diagnosis of suspected CD and for evaluation of disease activity (sensitivity 0.84, specificity 0.92), is widely available and noninvasive, but its accuracy is lower for disease proximal to the terminal ileum. MRI has a high diagnostic accuracy for the diagnosis of suspected CD and for evaluation of disease extension and activity (sensitivity 0.93, specificity 0.90), and is less dependent on the examiner and disease location compared with US. CT has a similar accuracy to MRI for assessment of disease extension and activity. The three techniques have a high accuracy for identification of fistulas, abscesses and stenosis (sensitivities and specificities >0.80), although US has false positive results for abscesses. As a result of the lack of radiation, US or MRI should be preferred over CT, particularly in young patients. Conclusions Cross-sectional imaging techniques have a high accuracy for evaluation of suspected and established CD, reliably measure disease severity and complications; they may offer the possibility to monitor disease progression. [ABSTRACT FROM AUTHOR]

The number and proportion of older U.S. adults who live alone have increased dramatically in the past three decades, and there is concern that these individuals may have particularly poor dietary quality. We examined the association of four living arrangements (living with a spouse only, with a spouse plus someone else, with someone other than a spouse or living alone) with dietary quality (the number of low nutrients out of a possible 15, with low defined as <67% of the recommended dietary allowance) among 6525 U.S. adults aged 50-64 y and those >/=65 y in the third National Health and Nutrition Examination Survey (NHANES III 1988-1994). Among non-Hispanic Caucasian adults, those who lived with a spouse only had better dietary quality, with significant differences ranging from 0.8 to 1.5 fewer low nutrients compared with those with other living arrangements. Effects of living arrangements on dietary quality were also seen among non-Hispanic African-Americans, Mexican-Americans, and those of "other" races, but differences were significant only for African-American men aged >65 y living with a spouse plus others (1.6 additional low nutrients compared with those living with a spouse only). Energy intake was strongly associated with dietary quality, but did not account for the associations between living arrangements and dietary quality. Although middle-aged and older adults with living arrangements other than living with a spouse only (including those living alone) tended to have poorer dietary quality, the effects varied substantially across age, gender and ethnic categories. [ABSTRACT FROM AUTHOR]

We have investigated the role of the utero-ovarian ligament (UOL) in the alternating ovulatory performance of ovaries in the capuchin monkey. In intact animals, the ovulation rate was near 90%, with 67.5% of ovulations occurring in the left ovary. Sectioning the UOL in any phase of the cycle decreased the ovulation rate by 40%, and restricted ovulations to the ovary still connected to the uterus by the UOL. Estradiol and progesterone levels were significantly reduced throughout the following cycles in treated monkeys. Removal of the ovary that had been disconnected 18-20 months previous, restored both the ovulation rate and normal steroid levels. Histological study of the UOL revealed the presence of arteries, veins, lymph vessels, and nerves. Electrical stimulation of the UOL was followed by an abrupt discharge of estradiol by the ovary bearing the follicle, advancing ovulation which was followed by a normal luteal development. Conversely, stimulation of the ovary bearing a corpus luteum did not modify either the ovarian or the peripheral levels of ovarian steroids. The UOL ligament appeared to be functional for products arising from the uterus. The distribution and effects of hCG injected intrauterinely depended upon the day of the luteal phase. In the early luteal phase, hCG was distributed symmetrically between both ovaries, and increased the progesterone secretion by the ovulatory ovary only. In the late luteal phase, hCG was preferentially distributed to the ovulatory ovary, and increased the progesterone secretion by both ovaries. The present findings provide evidence for a local mechanism, throughout the UOL, controlling both the alternation of ovulation and the transfer of substances originating in the uterus that regulate the ovarian function in primates. [ABSTRACT FROM AUTHOR]