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Spin-orbit coupling in noncentrosymmetric crystals leads to spin-momentum locking - a directional relationship between an electron's spin angular momentum and its linear momentum. Isotropic orthogonal Rashba spin-momentum locking has been studied for decades, while its counterpart, isotropic parallel Weyl spin-momentum locking has remained elusive in experiments. Theory predicts that Weyl spin-momentum locking can only be realized in structurally chiral cubic crystals in the vicinity of Kramers-Weyl or multifold fermions. Here, we use spin- and angle-resolved photoemission spectroscopy to evidence Weyl spin-momentum locking of multifold fermions in the chiral topological semimetal PtGa. We find that the electron spin of the Fermi arc surface states is orthogonal to their Fermi surface contour for momenta close to the projection of the bulk multifold fermion at the Γ point, which is consistent with Weyl spin-momentum locking of the latter. The direct measurement of the bulk spin texture of the multifold fermion at the R point also displays Weyl spin-momentum locking. The discovery of Weyl spin-momentum locking may lead to energy-efficient memory devices and Josephson diodes based on chiral topological semimetals.
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Background: Prolactinoma, the most common pituitary adenoma, is usually treated with dopamine agonist (DA) therapy like cabergoline. Surgery is second-line therapy, and radiotherapy is used if surgical treatment fails or in relapsing macroprolactinoma. Objective: This study aimed to provide economic evidence for the management of prolactinoma in Italy, using a cost-of-illness and cost-utility analysis that considered various treatment options, including cabergoline, bromocriptine, temozolomide, radiation therapy, and surgical strategies. Methods: The researchers conducted a systematic literature review for each research question on scientific databases and surveyed a panel of experts for each therapeutic procedure's specific drivers that contributed to its total cost. Results: The average cost of the first year of treatment was 2,558.91 and 3,287.40 for subjects with microprolactinoma and macroprolactinoma, respectively. Follow-up costs from the second to the fifth year after initial treatment were 798.13 and 1,084.59 per year in both groups. Cabergoline had an adequate cost-utility profile, with an incremental cost-effectiveness ratio (ICER) of 3,201.15 compared to bromocriptine, based on a willingness-to-pay of 40,000 per quality-adjusted life year (QALY) in the reference economy. Endoscopic surgery was more cost-effective than cabergoline, with an ICER of 44,846.64. Considering a willingness-to-pay of 40,000/QALY, the baseline findings show cabergoline to have high cost utility and endoscopic surgery just a tad above that. Conclusions: Due to the favorable cost-utility profile and safety of surgical treatment, pituitary surgery should be considered more frequently as the initial therapeutic approach. This management choice could lead to better outcomes and an appropriate allocation of healthcare resources.
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The two-dimensional electron system (2DES) located at the surface of strontium titanate (STO) and at several other STO-based interfaces has been an established platform for the study of novel physical phenomena since its discovery. Here we report how the interfacing of STO and tetracyanoquinodimethane (TCNQ) results in a charge transfer that depletes the number of free carriers at the STO surface, with a strong impact on its electronic structure. Our study paves the way for efficient tuning of the electronic properties, which promises novel applications in the framework of oxide/organic-based electronics.
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INTRODUCTION: This guideline (GL) is aimed at providing a reference for the management of prolactin (PRL)-secreting pituitary adenoma in adults. However, pregnancy is not considered. METHODS: This GL has been developed following the methods described in the Manual of the Italian National Guideline System. For each question, the panel appointed by Associazione Medici Endocrinologi (AME) has identified potentially relevant outcomes, which have then been rated for their impact on therapeutic choices. Only outcomes classified as "critical" and "important" have been considered in the systematic review of evidence and only those classified as "critical" have been considered in the formulation of recommendations. RESULTS: The present GL provides recommendations regarding the role of pharmacological and neurosurgical treatment in the management of prolactinomas. We recommend cabergoline (Cab) vs. bromocriptine (Br) as the firstchoice pharmacological treatment to be employed at the minimal effective dose capable of achieving the regression of the clinical picture. We suggest that medication and surgery are offered as suitable alternative first-line treatments to patients with non-invasive PRL-secreting adenoma, regardless of size. We suggest Br as an alternative drug in patients who are intolerant to Cab and are not candidates for surgery. We recommend pituitary tumor resection in patients 1) without any significant neuro-ophthalmologic improvement within two weeks from the start of Cab, 2) who are resistant or do not tolerate Cab or other dopamine-agonist drugs (DA), 3) who escape from previous efficacy of DA, and 4) who are unwilling to undergo a chronic DA treatment. We recommend that patients with progressive disease notwithstanding previous tumor resection and ongoing DA should be managed by a multidisciplinary team with specific expertise in pituitary diseases using a multimodal approach that includes repeated surgery, radiotherapy, DA, and possibly, the use of temozolomide. CONCLUSION: The present GL is directed to endocrinologists, neurosurgeons, and gynecologists working in hospitals, in territorial services or private practice, and to general practitioners and patients.
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Neoplasias Hipofisárias , Prolactinoma , Adulto , Humanos , Bromocriptina/uso terapêutico , Cabergolina/uso terapêutico , Agonistas de Dopamina/uso terapêutico , Ergolinas/uso terapêutico , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/terapia , Prolactina , Prolactinoma/terapia , Prolactinoma/tratamento farmacológicoRESUMO
Throughout the SARS-CoV-2 pandemic, the use of botanical dietary supplements in the United States has increased, yet their safety and efficacy against COVID-19 remains underexplored. The Quave Natural Product Library is a phylogenetically diverse collection of botanical and fungal natural product extracts including popular supplement ingredients. Evaluation of 1867 extracts and 18 compounds for virus spike protein binding to host cell ACE2 receptors in a SARS-CoV-2 pseudotyped virus system identified 310 extracts derived from 188 species across 76 families (3 fungi, 73 plants) that exhibited ≥ 50% viral entry inhibition activity at 20 µg/mL. Extracts exhibiting mammalian cytotoxicity > 15% and those containing cardiotoxic cardiac glycosides were eliminated. Three extracts were selected for further testing against four pseudotyped variants and infectious SARS-CoV-2 and were then further chemically characterized, revealing the potent (EC50 < 5 µg/mL) antiviral activity of Solidago altissima L. (Asteraceae) flowers and Pteridium aquilinum (L.) Kuhn (Dennstaedtiaceae) rhizomes.
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Produtos Biológicos , COVID-19 , Humanos , Animais , SARS-CoV-2 , Filogenia , Internalização do Vírus , Antivirais , Extratos Vegetais , Ligação Proteica , MamíferosRESUMO
BACKGROUND: The aim of this study was to analyze the risk factors for surgical infectious complications and the outcomes of patients undergoing surgery for perihilar cholangiocarcinoma according to the microbiological examinations. METHODS: Patients who underwent surgery for perihilar cholangiocarcinoma in the last decade were enrolled, and all clinical and microbiological data were collected from a retrospective monocentric database. Univariate and multivariate analyses were performed distinguishing patients who developed at least 1 surgical infectious complication (surgical site infections, acute bacterial cholangitis, bacteremia). RESULTS: A total of 98 patients were included. Among patients who developed surgical infectious complications (51%), many preoperative characteristics were significantly more frequent: American Society of Anesthesiologists score ≥3 (P = .026), neutrophil-to-lymphocyte ratio ≥3.4 (P = .001), endoscopic sphincterotomy (P = .032), ≥2 biliary drainage procedures (P = .013), acute cholangitis (P = .012), multidrug resistant (P = .009), and ≥3 microorganisms' detection (P = .042); whereas during the postoperative period, surgical infectious complications were associated to increased incidence of intensive care unit readmission (P = .031), major complications (P < .001), posthepatectomy liver failure (P = .005), ascites (P = .008), biliary leakage (P = .008), 90-day readmission (P = .003), and prolonged length of hospital stay (P < .001). At the multivariate analysis 3 independent preoperative risk factors for surgical infectious complications were identified: neutrophil-to-lymphocyte ratio ≥3.4 (P = .004), endoscopic sphincterotomy (P = .009), and acute cholangitis (P = .013). The presence of multidrug-resistance in the perioperative biliary cultures was related to postoperative multidrug-resistant species from all cultures (P < .001) and organ/space and incisional-surgical site infections (P ≤ .044). CONCLUSION: Infective complications after surgery for perihilar cholangiocarcinoma worsen the short-term outcomes. A careful microbiological surveillance should be carried out in all cases to prevent and promptly treat surgical infectious complications.
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Neoplasias dos Ductos Biliares , Colangiocarcinoma , Colangite , Tumor de Klatskin , Neoplasias dos Ductos Biliares/complicações , Neoplasias dos Ductos Biliares/cirurgia , Colangiocarcinoma/cirurgia , Colangite/epidemiologia , Colangite/etiologia , Drenagem/métodos , Humanos , Tumor de Klatskin/complicações , Tumor de Klatskin/cirurgia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/microbiologia , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologiaRESUMO
Prolactinomas are the most frequent pituitary adenomas. Prolactinoma may occur in different clinical settings and always require an individually tailored approach. This is the reason why a panel of Italian neuroendocrine experts was charged with the task to provide indications for the diagnostic and therapeutic approaches that can be easily applied in different contexts. The document provides 15 recommendations for diagnosis and 54 recommendations for treatment, issued according to the GRADE system. The level of agreement among panel members was formally evaluated by RAND-UCLA methodology. In the last century, prolactinomas represented the paradigm of pituitary tumors for which the development of highly effective drugs obtained the best results, allowing to avoid neurosurgery in most cases. The impressive improvement of neurosurgical endoscopic techniques allows a far better definition of the tumoral tissue during surgery and the remission of endocrine symptoms in many patients with pituitary tumors. Consequently, this refinement of neurosurgery is changing the therapeutic strategy in prolactinomas, allowing the definitive cure of some patients with permanent discontinuation of medical therapy.
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Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/terapia , Prolactinoma/diagnóstico , Prolactinoma/terapia , Criança , Consenso , Dopaminérgicos/efeitos adversos , Dopaminérgicos/uso terapêutico , Endocrinologia , Medicina Baseada em Evidências , Feminino , Humanos , Hiperprolactinemia/etiologia , Hiperprolactinemia/terapia , Itália , Masculino , Procedimentos Neurocirúrgicos/métodos , Neoplasias Hipofisárias/etiologia , Gravidez , Prolactinoma/etiologia , RadioterapiaRESUMO
The 2-dimensional electron gas (2DEG) found at the surface of SrTiO3 and related interfaces has attracted significant attention as a promising basis for oxide electronics. In order to utilize its full potential, the response of this 2DEG to structural changes and surface modification must be understood in detail. Here, a study of the detailed electronic structure evolution of the 2DEG as a function of sample temperature and surface step density is presented. By comparing the experimental results with ab initio calculations, it is shown that local structure relaxations cause a metal-insulator transition of the system around 135 K. This study presents a new and simple way of tuning the 2DEG via surface vicinality and identifies how the operation of prospective devices will respond to changes in temperature.
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Dirac fermions play a central role in the study of topological phases, for they can generate a variety of exotic states, such as Weyl semimetals and topological insulators. The control and manipulation of Dirac fermions constitute a fundamental step toward the realization of novel concepts of electronic devices and quantum computation. By means of Angle-Resolved Photo-Emission Spectroscopy (ARPES) experiments and ab initio simulations, here, we show that Dirac states can be effectively tuned by doping a transition metal sulfide, [Formula: see text], through Co/Ni substitution. The symmetry and chemical characteristics of this material, combined with the modification of the charge-transfer gap of [Formula: see text] across its phase diagram, lead to the formation of Dirac lines, whose position in k-space can be displaced along the [Formula: see text] symmetry direction and their form reshaped. Not only does the doping x tailor the location and shape of the Dirac bands, but it also controls the metal-insulator transition in the same compound, making [Formula: see text] a model system to functionalize Dirac materials by varying the strength of electron correlations.
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Employing X-ray magnetic circular dichroism (XMCD), angle-resolved photoemission spectroscopy (ARPES), and momentum-resolved density fluctuation (MRDF) theory, the magnetic and electronic properties of ultrathin NdNiO3 (NNO) film in proximity to ferromagnetic (FM) La0.67 Sr0.33 MnO3 (LSMO) layer are investigated. The experimental data shows the direct magnetic coupling between the nickelate film and the manganite layer which causes an unusual ferromagnetic (FM) phase in NNO. Moreover, it is shown the metal-insulator transition in the NNO layer, identified by an abrupt suppression of ARPES spectral weight near the Fermi level (EF ), is absent. This observation suggests that the insulating AFM ground state is quenched in proximity to the FM layer. Combining the experimental data (XMCD and AREPS) with the momentum-resolved density fluctuation calculation (MRDF) reveals a direct link between the MIT and the magnetic orders in NNO systems. This work demonstrates that the proximity layer order can be broadly used to modify physical properties and enrich the phase diagram of RENiO3 (RE = rare-earth element).
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BACKGROUND: The Aegadian Islands are located west of Trapani, Sicily. Once the site of bountiful tuna fisheries and fruit orchards (plums, peaches, apricots), grapevines, prickly pears, and grains, the local economy is now based on tourism, and many traditional agricultural and maritime practices have been abandoned. In this study, we aimed to evaluate the state of traditional ecological knowledge (TEK) concerning the use of wild and cultivated plants and fungi for human health, food, maritime, and agricultural purposes on the islands of Levanzo, Favignana, and Marettimo and compare present-day practices with those documented in the past. METHODS: In-depth semi-structured interviews were conducted in Italian with 48 participants with prior informed consent from May 2016 to July 2017 and October 2018. Herbarium voucher specimens of wild species were collected for herbarium deposit. A rigorous literature review of scientific and other local reports on TEK of wild flora and their application in food, health, and household applications was undertaken for the purpose of comparing findings from this field study with prior reports. RESULTS: A total of 122 plant and five fungal taxa representing 54 families were cited for 355 uses. Among the most pervasive species in the landscape, Agave americana and A. sisalana had diverse applications in the past, which ranged from cordage for agricultural and maritime applications to tools for sewing, eating land snails, and constructing furniture. Fields of Ferula communis also dominate the landscape, and the dry stems were used extensively in furniture making; this species also serves as an environmental indicator for the location of the most preferred edible mushrooms, Pleurotus eryngii var. ferulae. Other important flora included topical medicinal applications of Glaucium flavum for hematomas and Artemisia arborescens for ritual bathing of newborns. CONCLUSION: While many plant-based traditions have disappeared from daily practice, especially those related to traditional fishing and health practices, they remain in the memories of the eldest subset of the population. Documenting this knowledge before it disappears from oral history is a key factor in reducing loss of TEK and biocultural diversity, safeguarding the role of the Aegadian Islands as biocultural refugia.
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Etnobotânica , Plantas Medicinais , Agave , Artemisia , Humanos , Ilhas , Conhecimento , Papaveraceae , Pleurotus , Refúgio de Vida Selvagem , SicíliaRESUMO
Ferroelectric α-GeTe is unveiled to exhibit an intriguing multiple nontrivial topology of the electronic band structure due to the existence of triple-point and type-II Weyl fermions, which goes well beyond the giant Rashba spin splitting controlled by external fields as previously reported. Using spin- and angle-resolved photoemission spectroscopy combined with ab initio density functional theory, the unique spin texture around the triple point caused by the crossing of one spin-degenerate and two spin-split bands along the ferroelectric crystal axis is derived. This consistently reveals spin winding numbers that are coupled with time-reversal symmetry and Lorentz invariance, which are found to be equal for both triple-point pairs in the Brillouin zone. The rich manifold of effects opens up promising perspectives for studying nontrivial phenomena and multicomponent fermions in condensed matter systems.
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The design of epitaxial semiconductor-superconductor and semiconductor-metal quantum devices requires a detailed understanding of the interfacial electronic band structure. However, the band alignment of buried interfaces is difficult to predict theoretically and to measure experimentally. This work presents a procedure that allows to reliably determine critical parameters for engineering quantum devices; band offset, band bending profile, and number of occupied quantum well subbands of interfacial accumulation layers at semiconductor-metal interfaces. Soft X-ray angle-resolved photoemission is used to directly measure the quantum well states as well as valence bands and core levels for the InAs(100)/Al interface, an important platform for Majorana-zero-mode based topological qubits, and demonstrate that the fabrication process strongly influences the band offset, which in turn controls the topological phase diagrams. Since the method is transferable to other narrow gap semiconductors, it can be used more generally for engineering semiconductor-metal and semiconductor-superconductor interfaces in gate-tunable superconducting devices.
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In the high spin-orbit-coupled Sr2IrO4, the high sensitivity of the ground state to the details of the local lattice structure shows a large potential for the manipulation of the functional properties by inducing local lattice distortions. We use epitaxial strain to modify the Ir-O bond geometry in Sr2IrO4 and perform momentum-dependent resonant inelastic X-ray scattering (RIXS) at the metal and at the ligand sites to unveil the response of the low-energy elementary excitations. We observe that the pseudospin-wave dispersion for tensile-strained Sr2IrO4 films displays large softening along the [h,0] direction, while along the [h,h] direction it shows hardening. This evolution reveals a renormalization of the magnetic interactions caused by a strain-driven cross-over from anisotropic to isotropic interactions between the magnetic moments. Moreover, we detect dispersive electron-hole pair excitations which shift to lower (higher) energies upon compressive (tensile) strain, manifesting a reduction (increase) in the size of the charge gap. This behavior shows an intimate coupling between charge excitations and lattice distortions in Sr2IrO4, originating from the modified hopping elements between the t2g orbitals. Our work highlights the central role played by the lattice degrees of freedom in determining both the pseudospin and charge excitations of Sr2IrO4 and provides valuable information toward the control of the ground state of complex oxides in the presence of high spin-orbit coupling.
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Preparative high-performance liquid chromatographic (prep-HPLC) systems are used in many research schemes including purifying products from reaction mixtures, fractionating natural product extracts, and isolating compounds. Manual fraction collection from a prep-HPLC is a common method; however, it often lacks the reproducibility of automated fraction collectors due to human error. Automated fraction collectors for prep-HPLC systems can add thousands of dollars to the cost of prep-HPLC and are thus not always available to budgetary constrained research programs. Nevertheless, an automated fraction collector is a tremendous resource for any lab that employs prep-HPLC methods. Using LEGO MINDSTORMS pieces and easily obtained lumber and a steel C-channel, we were able to deploy an automated fraction collector for only a fraction of the cost of a commercial instrument. The programming software allows for a simple interface to create fraction collection programs tailored to individual HPLC methods. This fraction collector can be connected to any LC system and tailored to collect fractions in nearly any size or shaped container. This fraction collector was designed to provide maximum versatility and will make automated fraction collection more accessible to all researchers. The simple interface allows for quickly adapting the fraction collector method to any liquid chromatographic separation, no matter how complex.
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Automação , Software , Cromatografia Líquida de Alta Pressão/economia , Custos e Análise de Custo , HumanosRESUMO
Since their first appearance, organic-inorganic perovskite absorbers have been capturing the attention of the scientific community. While high efficiency devices highlight the importance of band level alignment, very little is known on the origin of the strong n-doping character observed in the perovskite. Here, by means of a highly accurate photoemission study, we shed light on the energy alignment in perovskite-based devices. Our results suggest that the interaction with the substrate may be the driver for the observed doping in the perovskite samples.
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Hemangioendotelioma is a group of rare vascular tumors with border-line behavior. They may involve internal organs, limbs, bones and soft tissue. The histological variant epitheliod hemangiothelioma is locally aggressive and has metastatic potential. We present a case of a 41-years old woman affected by epitheliod hemangiothelioma of the right quadriceps. The patient complained of localized pain in the anterior region of the right thigh, which started about 3 months earlier during physical exercise. For the increasing size of the lesion, the patient was referred to our Department. On physical examination, the lesion appeared elastic, fixed to the surrounding tissues and painful under pressure. An ultrasound examination revealed a small avascular lesion and a MRI examination showed an oval formation measuring about 18 mm in diameter of nonspecific significance. A surgical removal of the lesion was performed and diagnosis of epithelioid hemangiothelioma was achieved. A complete removal of the quadriceps muscle was then accomplished. In this paper, clinical and oncologic aspects of this rare tumor are discussed KEY WORDS: Epithelioid hemangiothelioma, Lower limbs tumor, Rare tumors.
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Hemangioendotelioma Epitelioide/cirurgia , Músculo Quadríceps/cirurgia , Neoplasias de Tecidos Moles/cirurgia , Adulto , Feminino , Hemangioendotelioma Epitelioide/diagnóstico , Hemangioendotelioma Epitelioide/diagnóstico por imagem , Hemangioendotelioma Epitelioide/patologia , Humanos , Músculo Quadríceps/diagnóstico por imagem , Músculo Quadríceps/patologia , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/patologia , Ultrassonografia DopplerRESUMO
Interfacing different transition-metal oxides opens a route to functionalizing their rich interplay of electron, spin, orbital, and lattice degrees of freedom for electronic and spintronic devices. Electronic and magnetic properties of SrTiO3-based interfaces hosting a mobile two-dimensional electron system (2DES) are strongly influenced by oxygen vacancies, which form an electronic dichotomy, where strongly correlated localized electrons in the in-gap states (IGSs) coexist with noncorrelated delocalized 2DES. Here, we use resonant soft-X-ray photoelectron spectroscopy to prove the eg character of the IGSs, as opposed to the t2g character of the 2DES in the paradigmatic LaAlO3/SrTiO3 interface. We furthermore separate the d xy and d xz/d xz orbital contributions based on deeper consideration of the resonant photoexcitation process in terms of orbital and momentum selectivity. Supported by a self-consistent combination of density functional theory and dynamical mean field theory calculations, this experiment identifies local orbital reconstruction that goes beyond the conventional eg- vs-t2g band ordering. A hallmark of oxygen-deficient LaAlO3/SrTiO3 is a significant hybridization of the eg and t2g orbitals. Our findings provide routes for tuning the electronic and magnetic properties of oxide interfaces through "defect engineering" with oxygen vacancies.
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PURPOSE: Presently, laparoscopic splenectomy (LS) is being performed for several indications in clinical practice. However, conversion to open surgery is occasionally required in some patients. We analyzed the intraoperative indications and potential preoperative predictors associated with conversion to open surgery in those presenting for LS. METHODS: We reviewed 107 patients who underwent LS. We analyzed the surgical indications, spleen size, surgical procedure performed, operative time, rate of and indications for conversions, as well as postoperative complications. RESULTS: Among the 15 patients (14.0%) who underwent conversion, the conversion was related to the occurrence of a splenic lymphoma in 10, severe bleeding in 3, a lack of anatomic definition in 1, and splenic candidiasis in 1 patient. A comparison between the results obtained in the initial 30 patients (LS performed during the learning curve) and those obtained in the remaining 77 patients, showed that conversions appeared to be related to the experience/expertise of the surgical team excluding patients with splenic malignancies. Conversion was not associated with a higher morbidity-mortality rate, but only a longer length of hospitalization. CONCLUSIONS: LS is a gold standard procedure when performed by experienced and competent surgeons. However, careful patient selection is recommended before using the laparoscopic approach in those presenting with splenic malignancies.
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Conversão para Cirurgia Aberta/estatística & dados numéricos , Laparoscopia/estatística & dados numéricos , Esplenectomia/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Complicações Intraoperatórias/etiologia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Tamanho do Órgão , Complicações Pós-Operatórias/etiologia , Cuidados Pré-Operatórios/métodos , Esplenectomia/métodos , Esplenopatias/cirurgia , Adulto JovemRESUMO
Vitamin D deficiency is very common and prescriptions of both assay and supplementation are increasing more and more. Health expenditure is exponentially increasing, thus it is timely and appropriate to establish rules. The Italian Association of Clinical Endocrinologists appointed a task force to review literature about vitamin D deficiency in adults. Four topics were identified as worthy for the practicing clinicians. For each topic recommendations based on scientific evidence and clinical practice were issued according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) System. (1) What cut-off defines vitamin D deficiency: even though 20 ng/mL (50 nmol/L) can be considered appropriate in the general population, we recommend to maintain levels above 30 ng/mL (75 nmol/L) in categories at risk. (2) Whom, when, and how to perform screening for vitamin D deficiency: categories at risk (patients with bone, liver, kidney diseases, obesity, malabsorption, during pregnancy and lactation, some elderly) but not healthy people should be screened by the 25-hydroxy-vitamin D assay. (3) Whom and how to treat vitamin D deficiency: beyond healthy lifestyle (mostly sun exposure), we recommend oral vitamin D (vitamin D2 or vitamin D3) supplementation in patients treated with bone active drugs and in those with demonstrated deficiency. Dosages, molecules and modalities of administration can be profitably individually tailored. (4) How to monitor the efficacy of treatment with vitamin D: no routine monitoring is suggested during vitamin D treatment due to its large therapeutic index. In particular conditions, 25-hydroxy-vitamin D can be assayed after at least a 6-month treatment. We are confident that this document will help practicing clinicians in their daily clinical practice.