Prospects for versatile phase manipulation in the TEM: beyond aberration correction

In this paper we explore the desirability of a transmission electron microscope in which the phase of the electron wave can be freely controlled. We discuss different existing methods to manipulate the phase of the electron wave and their limitations. We show how with the help of current techniques the electron wave can already be crafted into specific classes of waves each having their own peculiar properties. Assuming a versatile phase modulation device is feasible, we explore possible benefits and methods that could come into existence borrowing from light optics where so-called spatial light modulators provide programmable phase plates for quite some time now. We demonstrate that a fully controllable phase plate building on Harald Rose's legacy in aberration correction and electron optics in general would open an exciting field of research and applications.Comment: 9 pages, 4 figures, special Ultramicroscopy issue for PICO2015 conferenc

Diabetes and Cancer: Is there a Link?

Cancer and diabetes are two major health problems worldwide, and incidence is increasing globally for both diseases. Type 2 diabetes is characterized by hyperinsulinemia and insulin resistance and the effect of insulin and insulin growth factor I on cancer development and progression have been demonstrated in animal and human studies. The relationship between diabetes and cancer was reported for more than 60 years. Many epidemiological studies conducted over time suggested the association between diabetes and cancer. Epidemiological studies show an increased risk in type 2 diabetic patients for colon, breast, liver, pancreas, bladder cancers and non-Hodgkin’s lymphoma, and a decrease risk for prostate cancer. Lung cancer does not appear to be related to diabetes and for renal cancer data are inconclusive. Diabetes, beside the fact that it is an independent risk factor for different type of cancer, can also have an impact on prognosis of cancer, and studies shown an increased cancer mortality in patients with diabetes

Sinonasal inverted papilloma; recurrence, malignant transformation and risk factors

Sinonasal inverted papilloma is a rare benign epithelial tumor. Its three main clinical characteristics are the tendency of recurrence, the destructive ability of nearby structures and malignant transformation. The primary manifestations of this tumor include nasal obstruction, headaches, runny nose, hemorrhage and impaired sense of smell. The diagnosis is based on the clinical and endoscopic examination completed by CT or MRI scans and biopsy of the lesion. Allergies, chronic inflammation, nicotinism and viral infections such as HPV infection are considered possible causes of pathogenesis and potential risk factors for relapse and malignancy. The treatment for this condition is the complete removal of the tumor with disease-free margins. Postoperative follow-up is essential for the early detection of recurrence or malignant transformation. One of the most basic and important steps in managing these patients is to acknowledge the presence of the mentioned risk factors and avoid exposure. Due to the high risk of relapse, the follow-up must be aggressive and thorough and always include the endoscopic examination. In our article, we wish to highlight the importance of the proper surgical intervention, but also the difference in the overall outcome of the patient ensured by the correct management of the risk factors, allowing us to prevent recurrence and malignant transformation

Diabetes mellitus and necrotizing fasciitis – a deadly combination; case report

Necrotizing fasciitis is a rapidly destructive affliction of soft tissues, with a mortality rate that may reach 73% of the cases. It is characterized by a progressive inflammation and extended necrosis of the subcutaneous tissue and the fascia. Necrotizing fasciitis was first described in 1848, and later in 1920 Meleney identified 20 patients in China in which the infection was presumably triggered by hemolytic streptococcus, linking pathological bacteria to the condition. In 1952, Wilson coined the term necrotizing fasciitis although without successfully identifying the specific pathological bacteria involved. In most cases, both risk and aggravating factors are present, the main risk factors being diabetes mellitus, liver cirrhosis, renal failure, and immunosuppressant states. Location may vary, but most frequently the disease occurs in the limbs, the trunk, and the perineum. Treatment depends on the location and the time of diagnosis and may range from large incisions with extensive debridement to organ amputations such as those of the limbs or breasts. Treatment is complex and expensive, and besides surgery, includes the administration of broad-spectrum antibiotics, anti-inflammatory drugs, intensive therapy support, and long-term hospitalizations. The prognosis is guarded. The present case entails a 56-year old female patient who presented with many risk factors favoring the occurrence of necrotizing fasciitis, namely diabetes mellitus, liver cirrhosis (decompensated with ascites and portal encephalopathy phenomena), untreated hepatitis B infection, chronic renal failure with diabetic nephrotic syndrome, and obesity

The relationship between gut microbiota and spontaneous bacterial peritonitis in patients with liver cirrhosis - a literature review

Gut microbiota is an essential component in the pathogenesis of liver cirrhosis and its complications. There is a direct relationship between the gut and the liver called the gutliver axis through which bacteria can reach the liver through the portal venous blood. However, it remains unclear how bacteria leave the intestine and reach the fluid collection in the abdomen. A series of mechanisms have been postulated to be involved in the pathogenesis of spontaneous bacterial peritonitis (SBP) and other complications of liver cirrhosis, including bacterial translocation, bacterial overgrowth, altered intestinal permeability and dysfunctional immunity. The hepatic function may also be affected by the alteration of intestinal microbiota composition. Current treatment in SBP is antibiotic therapy, but lately, probiotics have been the useful treatment suggested to improve the intestinal barrier and prevent bacterial translocation. However, studies are contradictory regarding their usefulness. In this review, we will summarize the literature data on the pathogenesis of spontaneous bacterial peritonitis concerning the existence of a relationship with the microbiota and the useful use of probiotics

Simulated holographic three-dimensional intensity shaping of evanescent-wave fields

The size of bright structures in traveling-wave light fields is limited by diffraction. This in turn limits a number of technologies, for example, optical trapping. One way to beat the diffraction limit is to use evanescent waves instead of traveling waves. Here we apply a holographic algorithm, direct search, to the shaping of complex evanescent-wave fields. We simulate three-dimensional intensity shaping of evanescent-wave fields using this approach, and we investigate some of its limitations. (c) 2008 Optical Society of America.</p

Correlation Between Transthoracic Contrast-Enhanced Ultrasound and Pulse Oximetry in Hepatopulmonary Syndrome Diagnosis

The prevalence of hepatopulmonary syndrome (HPS) in the setting of cirrhosis ranges between 4 and 47% and its presence increases the mortality rate, especially when hypoxemia is present. Our study aim was to fix whether there is a correlation of results between two simple and non‐invasive procedures such as transthoracic contrast‐enhanced ultrasound (CEUS) and pulse oximetry, used for early detection of HPS in patients with liver cirrhosis, having as endpoint the improvement in their outcome. The rapid lung enhancement and delayed left ventricle enhancement of the saline solution, after at least three systolic beats during CEUS and pulse oximetry showing a SaO2 < 95%, were correlated and considered positive for the diagnosis of HPS. One hundred and sixty‐five (44%) of the total of 375 patients diagnosed with liver cirrhosis enrolled in the current study, with or without respiratory symptoms (dyspnea, clubbing, distal cyanosis, cough and/or spider angioma), showed positive criteria for HPS diagnosis during CEUS. SaO2 < 95% and PaO2 < 70 mmHg were found in 123 patients (33%) during pulse oximetry investigation. Pearson correlation index showed a good correlation between lung and heart CEUS findings and pulse oximetry (r = 0.97) for HPS diagnosis. CEUS and pulse oximetry results correlate and rapidly diagnose HPS, a highly fatal complication of liver cirrhosis (LC), guiding the future treatment by speeding up orthotopic liver transplant OLT recommendations to improve the survival rates

Metabolic Risk Factors in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent primary malignancy of the liver and it is one of the leading causes of cancer-related deaths worldwide. The global burden of hepatocellular carcinoma is growing nowadays. Most cases of hepatocellular carcinoma develop in the background of chronic hepatitis C and B and liver cirrhosis‑well-known risk factor. But despite the reducing incidence of chronic hepatitis infections, an increase in the incidence of hepatocellular carcinoma was observed in the last decades. This could be explained by the increasing prevalence of obesity, type 2 diabetes mellitus, nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH), which are becoming important risk factors in hepatocellular carcinoma. Regular surveillance, as performed for patients with viral hepatitis, is required for patients with metabolic risk factors

Metformin and Its Implication in Cancer Therapy

Metformin has been used for almost half a century as the first line of treatment for type 2 diabetes. Mechanisms of action are still incompletely known, recent studies have shown that metformin exerts its effects through several mechanisms, including the stimulation of AMP-activated protein kinase, decreasing production of cyclic AMP, inhibition of mitochondrial complex I of the electron transport chain, targeting glycerophosphate dehydrogenase and altering gut microbiota. In recent years, studies have shown that patients with type 2 diabetes mellitus have a lower risk of developing cancer, and patients with cancer and type 2 diabetes have a lower mortality. Experimental studies have demonstrated that metformin has anti-tumor activity by inhibiting mTORC1 signaling pathway and mitochondrial complex, inhibiting tumor growth and proliferation, and inducing cellular apoptosis. There are multiple studies showing that combination of metformin with different types of anti-cancer therapies may reduce toxicities and tumor resistance. This chapter is focused on the progress made in understanding the anti-tumor effect of metformin and its association with cancer therapy