Large intrinsic anomalous Hall effect in SrIrO3 induced by magnetic proximity effect

The anomalous Hall effect (AHE) is an intriguing transport phenomenon occurring typically in ferromagnets as a consequence of broken time reversal symmetry and spin-orbit interaction. It can be caused by two microscopically distinct mechanisms, namely, by skew or side-jump scattering due to chiral features of the disorder scattering, or by an intrinsic contribution directly linked to the topological properties of the Bloch states. Here we show that the AHE can be artificially engineered in materials in which it is originally absent by combining the effects of symmetry breaking, spin orbit interaction and proximity-induced magnetism. In particular, we find a strikingly large AHE that emerges at the interface between a ferromagnetic manganite (La_0.7Sr_0.3MnO₃) and a semimetallic iridate (SrIrO₃). It is intrinsic and originates in the proximity-induced magnetism present in the narrow bands of strong spin-orbit coupling material SrIrO₃, which yields values of anomalous Hall conductivity and Hall angle as high as those observed in bulk transition-metal ferromagnets. These results demonstrate the interplay between correlated electron physics and topological phenomena at interfaces between 3d ferromagnets and strong spin-orbit coupling 5d oxides and trace an exciting path towards future topological spintronics at oxide interfaces.

Translating instruments into multiple Mayan languages for a hypertension T4 study in Guatemala

Issue

Guatemala is a culturally and linguistically diverse country. Mayan languages are primarily spoken languages; few people know their written form. Health features and outcomes are difficult to assess due to the lack of validated instruments in these languages.

Description of the Problem

A cluster randomized trial to improve hypertension control is being conducted in 36 municipalities where Mayan languages are spoken in addition to Spanish. Instruments for measuring study outcomes were developed in Spanish and cross-culturally adapted into five Mayan languages following WHO's methodology. First, data were gathered on the proportion of people only fluent in a Mayan language in each district. We prioritized those Mayan languages spoken by more than 20% of the non-Spanish speaking population: Achí, K'iche', Kaqchikel, Tz'utujil and Mam. Second, forward translation to the Mayan languages was conducted by a local healthcare professional, who verbally recorded each instrument. The study team identified key words and concepts to guarantee content equivalence. Third, back-translation was conducted by two independent healthcare providers, who were blinded to the original instruments. The research team formally compared the original questionnaires with the back-translated versions to ensure they were conceptually equivalent and culturally adapted. Discrepancies were corrected as needed. Finally, local interviewers were trained on how to accurately use the written Spanish questionnaires and the Mayan language verbal recordings.

Results

By following this methodology, we achieved cross-culturally adapted instruments to improve the information-gathering process in communities where only Mayan languages are spoken.

Lessons

Having culturally adapted tools will allow researchers to reach a broader range of the target population, obtain more accurate information, and take into account participants' culture and cosmovision.

Key messages

Translating questionnaires to people’s native language allows researchers to obtain more accurate information in a standardized way and better understand participants’ culture and cosmovision. The described methodology is beneficial for conducting research in linguistically diverse countries. It promotes effective and inclusive communication among researchers and participants.

Ursolic acid: A novel antiviral compound inhibiting rotavirus infection in vitro

Rotavirus is one of the leading causes of severe acute gastroenteritis in children under 5 years of age, mainly affecting developing countries. Once the disease is acquired, no specific treatment is available; as such, the development of new drugs for effective antirotaviral treatment is critical. Ursolic acid is a pentacyclic triterpenoid with antiviral activity, which has been studied extensively in vitro and in vivo. To study the potential antirotaviral activity of ursolic acid, its toxic potential for viral particles (virucidal effect) and cultured cells (cytotoxicity) was analysed. No effect on virion infectivity was observed with treatments of up to 40 µM ursolic acid, while incipient cytotoxicity started to be evident with 20 µM ursolic acid. The antiviral potential of ursolic acid was evaluated in in-vitro rotavirus infections, demonstrating that 10 µM ursolic acid inhibits rotavirus replication (observed by a decrease in viral titre and the level of the main viral proteins) and affects viral particle maturation (a process associated with the endoplasmic reticulum) 15 h post infection. Interestingly, ursolic acid was also found to hamper the early stages of the viral replication cycle, as a significant reduction in the number and size of viroplasms, consistent with a decrease in VP6 and NSP2 viral proteins, was observed 4 h post infection. As such, these observations demonstrate that ursolic acid exhibits antiviral activity, suggesting that this chemical could be used as a new treatment for rotavirus.

Building a network for multicenter, prospective research of central nervous system infections in South America: Process and lessons learned

Multicenter collaborative networks are essential for advancing research and improving clinical care for a variety of conditions. Research networks are particularly important for central nervous system infections, which remain difficult to study due to their sporadic occurrence and requirement for collection and testing of cerebrospinal fluid. Establishment of long-term research networks in resource-limited areas also facilitates diagnostic capacity building, surveillance for emerging pathogens, and provision of appropriate treatment where needed. We review our experience developing a research network for encephalitis among twelve hospitals in five Peruvian cities since 2009. We provide practical suggestions to aid other groups interested in advancing research on central nervous system infections in resource-limited areas.

A chimeric baculovirus displaying bovine herpesvirus-1 (BHV-1) glycoprotein D on its surface and their immunological properties

The ability of a recombinant baculovirus containing the ectodomain of the mature sequence of glycoprotein D (gD) fused to the amino-terminus of baculoviral glycoprotein gp64 to display gD on its surface and to serve as an improved immunogen against bovine herpesvirus-1 was tested. The gD-gp64 fusion protein was correctly expressed on the virus particles as revealed by immunomicroscopy assays. Mice immunized with 5 x 10(8) plaque forming units developed antibodies that specifically reacted in an enzyme-linked immunosorbent assay with recombinant gD and whole bovine herpesvirus-1. These antibodies were able to neutralize bovine herpesvirus-1 in vitro, whereas those elicited by a version of gD expressed in Escherichia coli did not. Our data demonstrated that the display on the virion surface of recombinant baculovirus can provide a tool for the development of recombinant vaccines against bovine herpesvirus-1.

Placental volume in twin and triplet pregnancies measured by three-dimensional ultrasound at 11 + 0 to 13 + 6 weeks of gestation

OBJECTIVE

To compare the placental volume at 11 + 0 to 13 + 6 weeks' gestation between singleton and multiple pregnancies and to examine the possible effect of chorionicity on placental volume.

METHODS

The placental volume was measured by three-dimensional (3D) ultrasound using the Virtual Organ Computer-aided AnaLysis (VOCAL) technique in 290 consecutive twin and 37 triplet pregnancies at 11 + 0 to 13 + 6 weeks of gestation. For the comparison of twin, triplet and singleton placental volumes each measurement was expressed as a multiple of the median (MoM) for singletons, previously established from the study of 417 normal fetuses at 11 + 0 to 13 + 6 weeks of gestation.

RESULTS

Median twin and triplet placental volumes were 1.66 and 2.28 MoM for singletons, respectively. In twins the placental volumes increased significantly with gestation from a median of 83.6 mL (5th and 95th centiles: 56.0 mL and 124.9 mL) at 11 + 0 weeks to 149.3 mL (5th and 95th centiles: 100.0 mL and 223.1 mL) at 13 + 6 weeks. The median MoM in monochorionic twins was not significantly different from that in dichorionic twins with fused placentas or dichorionic twins with separate placentas. In triplets the placental volumes increased significantly with gestation from a median of 114.9 mL (5th and 95th centiles: 77.6 mL and 170.1 mL) at 11 weeks to 217.9 mL (5th and 95th centiles: 147.2 mL and 322.5 mL) at 13 + 6 weeks. There were no significant differences in total placental volume between monochorionic and dichorionic triplets, monochorionic and trichorionic triplets, or dichorionic and trichorionic triplets.

CONCLUSIONS

Placental volume in multiple pregnancies does not depend on chorionicity, and the rate of placental growth between 11 and 13 + 6 weeks is not significantly different between singletons, twins and triplets. Moreover, for a given gestational age the placental volume corresponding to each fetus in twins and triplets is 83% and 76%, respectively, of the placental volume in singletons.

Elastic interaction of surface steps: effect of atomic-scale roughness

Elastic interactions of atomic steps can greatly impact surface morphology. Recent atomistic calculations and experimental observations find the standard dipole model of steps is valid only for very large step separations. In this Letter, a new model is presented that displays remarkable agreement with atomistic predictions for step separations larger than just a few step heights. It is shown that the interaction energy of steps exhibits a novel intermediate-ranged behavior and that, for particular systems, step interactions switch from repulsive to attractive as separation distance decreases.

Symptom management in hospice and palliative care

Managing the symptoms of advanced disease at the end of life is one of the most challenging aspects of medicine for most clinicians. Traditional textbooks provide limited resources for treating patients at this stoichiometric point in their disease. This article provides an overview in the treatment of common symptoms at the end of life, such as anxiety, anorexia and cachexia, constipation, delirium, dyspnea, fatigue and asthenia, nausea and vomiting, malignant intestinal obstruction, and terminal restlessness. By addressing these symptoms, the physician can play a key role in the patient's achievement of a peaceful, symptom-free, and dignified death in the setting of their choice.

Induction of a protective antibody response to foot and mouth disease virus in mice following oral or parenteral immunization with alfalfa transgenic plants expressing the viral structural protein VP1

The utilization of transgenic plants expressing recombinant antigens to be used in the formulation of experimental immunogens has been recently communicated. We report here the development of transgenic plants of alfalfa expressing the structural protein VP1 of foot and mouth disease virus (FMDV). The presence of the transgenes in the plants was confirmed by PCR and their specific transcription was demonstrated by RT-PCR. Mice parenterally immunized using leaf extracts or receiving in their diet freshly harvested leaves from the transgenic plants developed a virus-specific immune response. Animals immunized by either method elicited a specific antibody response to a synthetic peptide representing amino acid residues 135-160 of VP1, to the structural protein VP1, and to intact FMDV particles. Additionally, the immunized mice were protected against experimental challenge with the virus. We believe this is the first report demonstrating the induction of a protective systemic antibody response in animals fed transgenic plants expressing a viral antigen. These results support the feasibility of producing edible vaccines in transgenic forage plants, such as alfalfa, commonly used in the diet of domestic animals even for those antigens for which a systemic immune response is required.

Medical physics is alive and well and growing in South East Asia

In recent years there has been a significant economic growth in South East Asia, along with it a concurrent development of medical physics. The status of four countries--Malaysia, Thailand, the Philippines and Indonesia are presented. Medical physicists in these countries have been experiencing the usual problems of lack of recognition, low salaries, and insufficient facilities for education and training opportunities. However the situation has improved recently through the initiative of local enthusiastic medical physicists who have started MS graduate programs in medical physics and begun organizing professional activities to raise the profile of medical physics. The tremendous support and catalytic roles of the American Association of Physicists in Medicine (AAPM) and international organizations such as International Organization for Medical Physics (IOMP), International Atomic Energy Agency (IAEA), World Health Organization (WHO), and International Center for Theoretical Physics (ICTP) have been instrumental in achieving progress. Contributions by these organizations include co-sponsorship of workshops and conferences, travel grants, medical physics libraries programs, and providing experts and educators. The demand for medical physicists is expected to rise in tandem with the increased emphasis on innovative technology for health care, stringent governmental regulation, and acceptance by the medical community of the important role of medical physicists.

Evolution of patients with clinical neurocardiogenic (vasovagal) syncope not subjected to specific treatment

The purpose of this prospective study was to analyze the natural history of patients with clinical neurocardiogenic syncope. The results obtained with some therapeutic strategies in the prevention of neurocardiogenic syncope are encouraging. However, the benefit they represent when compared with the natural history of syncope has not been clearly established. Fifty-six consecutive patients with either (1) one or more episodes of syncope and a positive head-up tilt test or (2) typical history of vasovagal syncope despite a negative tilt test were monitored during a mean period of 16.1 +/- 10.2 months. Patients were discharged without any specific medication. There were no deaths during the follow-up period. Recurrences were found in 5 (8.9%) patients. The risk of recurrence was 7% after 1 year and 15% after 21 months. The prognosis of patients with clinical neurocardiogenic syncope is excellent as far as survival is concerned. Recurrences of episodes without specific treatment were uncommon after diagnosis had taken place. This finding strengthens the need to evaluate the effect of drugs with placebo control groups and to select the highest-risk group for treatment.

[Growth retardation, GH deficiency, hyperprolactinemia and delayed puberty]

A case of a male eleven years and three months old, brought to medical attention for short height, is reported. A deficiency of growth hormone associated with hyperprolactinemia without previous clinical manifestations is appreciated in endocrinological study. Detectable tumor is not apparent in any of the investigations performed. HGH and bromocriptine therapy is initiated, resulting in and increase in height and a decrease of prolactin. Currently, at fifteen years four months of age, clinical and analytical data suggest a case of hypogonadism and puberal retardation as well.

[Trisomy 5p: a report of 2 cases]

Authors report two patients from different families who present similar abnormalities caused by an "almost complete" trisomy of the short arm of chromosome 5 [case No. 1: 46, XY, der (20), t (5; 20) (p11;p13), mat; case No.2: 46, XY, dup (5p)]. Several family members of case No. 1 were balanced translocation carriers. Case No. 2 is probably due to de novo duplication. Clinical findings in our cases and those cited in the literature allow identification of certain main features characteristic of "almost complete" trisomy 5p: hypotonia, weak cry, mongoloid slant of eyes, epicanthus, depressed nasal bridge, auricular anomalies, bilateral cryptorchidism and, less frequently, macrocephaly, micrognathia and club feet.

[Precocious pseudopuberty secondary to granulosa cell tumor]

A case report of pseudoprecocity secondary to a unilateral ovarian tumor of granulosa cells is presented in a 13 month old female. Clinical manifestations appeared at two months of age as unilateral enlargement of the breast, development of pubic hair and vaginal discharge. Plasma estrogen levels were elevated, whereas there was no response of FSH and LH to LH-RH stimulation. The absence of a palpable abdominal mass and a normal ultrasound examination of the abdomen must be pointed out in our case. The suspected clinical and laboratory diagnosis was later confirmed by surgical abdominal examination and ovarian histopathology study. With the exception of a minimal breast enlargement which persists at two years of age, all other signs of pseudoprecocity have disappeared after the surgical removal of the neoplasm. The importance of surgical abdominal examination must be pointed out as a diagnostic method when clinical and laboratory findings suggest an ovarian tumor inspite of normal abdominal palpation, ultrasound and roentgenology.

[Early detection of congenital hypothyroidism. Study of 31,609 determinations]

As a result of congenital hypothyroidism (CH) early detection program carried out in our clinic during the period 1978-1981, 31.609 capillary blood samples (35,7% from newborn infants) were taken on filter paper cards. An evaluation of TSH following the specific radioimmunoanalysis technique was made in all the samples, and an evaluation of T4 whenever TSH values were higher than 25 microU/ml serum. Thirteen cases of CH were detected: nine with permanent H and four with transient H. Two cases of hyperthyrotropinemia were also detected. Frequency of permanent CH in our population is of 1/3.512. Corresponding biochemical data and detailed clinical characteristics detected, including the cost of the procedure are shown. Authors emphasize on possibility of preventing brain damage and subsequent subnormality through early detection and treatment of congenital hypothyroidism, together with a suitable cost-benefit ratio, makes necessary to carry out a nationwide campaign in accordance with those centers already established.

[Partial 10q trisomy (q24;q ter) caused by a balanced maternal translocation t(6;10)(q26;q24)]

Authors have had the opportunity to study a patient affected by a malformative syndrome with severe motricity and mental retardation. Physical findings (namely: spacious forehead, flat and round face, small palpebral fissures, hypotonicity and growth retardation) are similar to the phenotype previously described in trisomy 10q. Chromosomal diagnosis failed until G, Q and R banding technique was applied. With this technique a partial 10q trisomy (q24 leads to q ter) due to a maternal translocation t(6:10)(q26;q24) was found.

[Thrombocytopenia-absent radius syndrome (author's transl)]

A patient affected with thrombocytopenia and bilateral absence of radius is described. Authors present data suggesting an acquired etiology: intrauterine cytomegalovirus infection and X-ray exposure during the ovulatory period. Patient showed some radiological features not previously described: methacarpian synostosis and absence of sternum ossification centers. Anemia was etiologically related to the iron deficiency secondary to bleeding. Chronic diarrhea, a feature common in this syndrome, was caused by cow's milk protein intolerance, other causes of chronic diarrhea, like pancreatic malfunction or disaccharidal intolerance were discarted. Finally comments on the differential diagnosis of the illness, its' evolution and treatment, pointing out the possibility of an intrauterine diagnosis, crucial for a correct genetic counselling are made.

[9p trisomy syndrome. Two new cases (author's transl)]

Two cases of trisomy 9p, are reported affecting different break points involving chromosome 9; one of them showed skeletal abnormalities of importance. An analysis of the two cases reported is done and some of the last hypothesis in order to determine genetical and clinical correlations of the syndrome are considered.

Partial trisomy 14q

A dysmorphic female born with partial trisomy of the proximal segment of the long arm of chromosome 14 had 47 chromosomes. The extra one was acrocentric, smaller than the D group, and bigger than the G-chromosome group. By GTG banding it was identified as a deleted chromosome 14, the karyotype being 47,XX,+del 14(q24). Chromosome analysis of the parents was normal.

[Turner's syndrome (author's transl)]

Twenty cases of Turner's syndrome are presented. Ten cases showed cariotype XO, nine XO/XX and one case showed mosaicism with three cell lines one of which showed a ring chromosome (XO/XX/XXr). The clinical characteristics of syndrome and the associated malformations are appraised. Commentaries are made about ultimate height attained by this patients.

Two new cases of true hermaphroditism

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