Exploiting the optical quadratic nonlinearity of zincblende semiconductors for guided-wave terahertz generation: a material comparison

We present a detailed analysis and comparison of dielectric waveguides made of CdTe, GaP, GaAs and InP for modal phase matched optical difference frequency generation (DFG) in the terahertz domain. From the form of the DFG equations, we derived the definition of a very general figure of merit (FOM). In turn, this FOM enabled us to compare different configurations, by taking into account linear and nonlinear susceptibility dispersion, terahertz absorption, and a rigorous evaluation of the waveguide modes properties. The most efficient waveguides found with this procedure are predicted to approach the quantum efficiency limit with input optical power in the order of kWs.Comment: 8 pages in two columns format, 6 figures, 2 Table

Surgical Treatment Strategies and Prognosis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC is the fifth most common cause of mortality worldwide and the third cancer related cause and is responsible for about 1 million deaths yearly [1]. The ageadjusted worldwide incidence is 5.5-14.9 per 100.000 population. In some areas of the world, such as sub-Saharan Africa and Southeast Asia, HCC represents the first cause of cancer death with an incidence of 52 per 100.000. Furthermore, in Europe and USA, HCC incidence has progressively raised in the past decade representing a burden problem. HCC is one of the few cancers for which a number of risk factors are known in great detail [2, 3]. HCC is almost always (80%) associated with cirrhosis, at least in developed countries, and chronic hepatitis C and B infection, alcoholic cirrhosis and haemocromatosis are some of the established risk factors [4]. The metabolic syndrome related to hypertension, central obesity, diabetes and obesity has been identified as a new risk factor. As a result, screening programs have developed, with the use of ultrasound and \u3b1-fetoprotein (AFP), with a hope to increase the chances of diagnosing small HCC and unltimately increase the rate of curability. Definitive diagnosis relies on the demonstration of a typical vascular pattern per liver imaging techniques (triple-phase CT-scan or MRI) of tumors larger than 2 cm with arterial hypervascularity and venous wash- out. Nodules, smaller than 2 cm, should be rechecked every six months or, if highly suspect, subjected to needle biopsy. It\u2019s likely that the study of tumor-specific tissue markers with prognostic value could introduce a systematic use of needle biopsy. Over the past 20 years, surgical treatment of hepatocellular carcinoma has seen an immense boost and improvement, with good survival outcomes and reduced morbidity and mortality.Liver resection (LR) and orthotopic liver transplantation (OLT) and ablative therapies are now considered the only potentially curative treatments for this cancer. LR has achieved improvement in survival within the past decade as a result of advances in diagnosis, surgical management of HCC and perioperative care. However, the long-term prognosis remains poor, and the 5-year overall survival rate ranges between 33% and 44%, with a 5-year cumulative recurrence rate of 80% to 100%. OLT could be viewed as the optimal treatment for HCC that is accompanied by advanced cirrhosis because of the widest possible resection margins for tumour and for a definitive cure of cirrhosis and its related complications. OLT for HCC performed within well-defined oncologic criteria (Milan criteria \u201creference\u201d) has shown long-term results comparable with those of transplantation for non-HCC patients. However, the critical shortage of available donated organs, together with the increasing number of patients awaiting transplantation, makes this therapeutic option available to only a small percentage of patients. Owing to the limited organ supply, many liver transplant centers usually make a selection to resect patients with compensated liver cirrhosis, defined as Child\u2013Pugh A chronic liver disease and resectable tumor and to reserve transplantation for those with impaired liver function (Child-Pugh class B-C) and small oligonodular HCC considered within the currently accepted criteria for transplantation. Radiofrequency and microwave ablation are relatively new percutaneous techniques in clinical use for HCC, that can produce tumour necrosis. Complete response rates are high in large series if tumour is less that 3 cm in diameter. This chapter will consider the main surgical techniques for the treatment of HCC in the light of the major guidelines currently available and of personal experience. Also, we will review HCC prognostic factors, and the particular situation of \u201clarge\u201d HCC and the strategy for liver tumours located at the hepato-caval confluence

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

La Plata basin precipitation variability in spring: role of remote SST forcing as simulated by GCM experiments

An ensemble of nine experiments with the same interannually varying sea sur face temperature (SST), as boundary forcing, and different initial conditions is used to investigate the role of tropical oceans in modulating precipitation variability in the region of La Plata Basin (LPB). The results from the ensemble are compared with a 20th-century experiment performed with a coupled ocean-atmosphere model, sharing the same atmospheric component. A rotated empirical orthogonal functions analysis of South America precipitation shows that the dominant mode of variability in spring is realistically captured in both experiments. Its principal component (RPC1) correlated with global sea surface temperature (SST) and atmospheric fields identifies the pattern related to El Nin?o Southern Oscillation and its large-scale teleconnections. Overall the pattern is well simulated in the tropical southern Pacific Ocean, mainly in the ensemble, but it is absent or too weak in other oceanic areas. The coupled model experiment shows a more realistic correlation in the subtropical South Atlantic where air-sea interactions contribute to the relationship between LPB precipitation and SST. The correspondence between model and data is much improved when the composite analysis of SST and atmospheric fields is done over the ensemble members having an RPC1 in agreement with the observations: the improvement relies on avoiding climate noise by averaging only over members that are statistically similar. Furthermore, the result suggests the presence of a high level of uncertainty due to internal atmospheric variability. The analysis of some individual years selected from the model and data RPC1 comparison reveals interesting differences among rainy springs in LPB. For example, 1982, which corresponds to a strong El Nin?o year, represents a clean case with a distinct wave train propagating from the central Pacific and merging with another one from the eastern tropical south Indian Ocean. The year 2003 is an example of a rainy spring in LPB not directly driven by remote SST forcing. In this case the internal variability has a dominant role, as the model is not able to reproduce the correct local precipitation pattern.Fil: Cherchi, Annalisa. Istituto Nazionale di Geofisica e Vulcanologia. Centro Euromediterraneo sui Cambiamenti Climatici; ItaliaFil: Carril, Andrea Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos; ArgentinaFil: Menendez, Claudio Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos; ArgentinaFil: Zamboni, Laura. Argonne National Laboratory. Mathematics and Computer Science Division; Estados Unido

Maternal Carbamazepine Therapy and Unusual Adverse Effects in a Breastfed Infant

Usually, no adverse effects are observed in breastfed infants whose mothers are treated with the anti-epileptic carbamazepine. In this article, we described unusual short-term adverse effects observed in a young infant after exposure to carbamazepine during pregnancy and lactation

Computed tomography-guided cryoablation of pelvic metastasis from uterine leiomyosarcoma

Owing to its ability to place and use multiple cryoprobes simultaneously, cryoablation enables the treatment of tumors of any shape. Cryoablation causes ice crystals to form within cells, inducing membrane rupture and cell death via cellular dehydration and local tissue ischemia. Ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) enable clear visualization of the margins of low-density and solid ice. A case of breast cancer with axillary lymph-node metastasis treated with CT-guided cryoablation has been reported previously

Cesarean Section and Right Femur Fracture: A Rare but Possible Complication for Breech Presentation

Background. The breech extraction of the fetus through the vagina has a greater risk of hip fracture compared with the extraction by abdominal route. Case. A 2390 g female infant was delivered at 39 weeks by elective cesarean section for breech presentation. The newborn sustained a fracture of the right femur. A simple immobilization of the limb in extension led to a complete healing of the fracture without sequelae. Conclusion. Caesarean delivery reduces the risk of causing a traumatic injury of the newborn compared to vaginal delivery, especially with breech presentation but does not eliminate this possible accidental complication

Two novel mutations in exon 3 of PHOX2B gene: think about congenital central hypoventilation syndrome in patients with Hirschsprung disease

Abstract Background Congenital central hypoventilation syndrome (CCHS) is characterized by alveolar hypoventilation increasing during sleep and affected patients are unable to perceive and respond to hypercarbia with increased ventilation and arousal during sleep. PHOX2B gene mutations are considered as responsible for CCHS. Most of patients with CCHS are heterozygous for polyalanine expansion mutations (PARMs) in exon 3, but 10% of patients with classic CCHS are heterozygous for non-polyalanine expansion mutations (NPARMs) of the PHOX2B gene. Methods Data are collected on 3 patients affected by CCHS who referred to the Paediatric Pulmonology Unit of Bambino Gesù Children’s Hospital (Rome, Italy) for a multidisciplinary follow-up program between 2000 and 2017. Results We describe three cases of patients affected by CCHS for which two novel mutations on exon 3 of PHOX2B gene were detected. Conclusions The description of these novel mutations and related clinical phenotypes allows to expand the knowledge into NPARM spectrum. Since the presence of Hirschsprung disease is related to NPARMs and the number of alanine repeats, we suggest performing CCHS genetic investigation and periodical assessment also in patients without a clear history of CCHS but affected by Hirschsprung disease. Trial registration Data are retrospectively collected