Wafer-scale graphene-ferroelectric HfO2/Ge-HfO2/HfO2 transistors acting as three-terminal memristors.

In this paper we report a set of experiments at the wafer level regarding field-effect transistors with a graphene monolayer channel transferred on the ferroelectric HfO2/Ge-HfO2/HfO2 three-layer structure. This kind of transistor has a switching ratio of 103 between on and off states due to the bandgap in graphene induced by the ferroelectric structure. Both top and back gates effectively control the carriers' charge flow in graphene. The transistor acts as a three-terminal memristor, termed a memtransistor, with applications in neuromorphic computation.

A Novel Method of Obtaining Platelet Rich Fibrin from Rats and Quantifying Platelet Count.

BACKGROUND AND OBJECTIVES: Rat experimentation is the first line of research by which a medical hypothesis is usually tested. Platelet Rich Fibrin (PRF) is a relatively new bio-material that has shown promise to enhance healing in the field of bone research and tissue engineering. In order to perform PRF based experiments on rats, a proper protocol of obtaining PRF from rats needs to be established. MATERIALS AND METHODS: 35 Wistar rats were used to obtain PRF by using cardiac puncture blood draw and quick subsequent centrifugation. The PRF samples wereanalyzed and compared to standard literature PRF composition. RESULTS: PRF samples analysis showed persistent results pertaining to known PRF composition. CONCLUSIONS: Our experiment has shown that our protocol of obtaining PRF is capable of providing high quality PRF from rats.

Orthorhombic HfO2 with embedded Ge nanoparticles in nonvolatile memories used for the detection of ionizing radiation.

Trilayer memory capacitors of control HfO2/floating gate of Ge nanoparticles in HfO2/tunnel HfO2/Si substrate deposited by magnetron sputtering and subsequently annealed are investigated for the first time for applications in radiation dosimetry. In the floating gate (FG), amorphous Ge nanoparticles (NPs) are arranged in two rows inside the HfO2 matrix. The HfO2 matrix is formed of orthorhombic/tetragonal nanocrystals (NCs). The adjacent thin films to the FG are also formed of orthorhombic/tetragonal HfO2 NCs. This phase is formed during annealing, in samples with thick control HfO2, in the presence of Ge, being induced by the stress. In the rest of the control oxide, HfO2 NCs are monoclinic. Orthorhombic HfO2 has ferroelectric properties and therefore enhances the memory window produced by charge storage in Ge NPs to above 6 V. The high sensitivity of 0.8 mV Gy-1 to α particle irradiation from a 241Am source was measured by monitoring the flatband potential during radiation exposure after electrical writing of the memory.

Efficacy of annealing and fabrication parameters on photo-response of SiGe in TiO2 matrix.

SiGe nanoparticles dispersed in a dielectric matrix exhibit properties different from those of bulk and have shown great potential in devices for application in advanced optoelectronics. Annealing is a common fabrication step used to increase crystallinity and to form nanoparticles in such a system. A frequent downside of such annealing treatment is the formation of insulating SiO2 layer at the matrix/SiGe interface, degrading the optical properties of the structure. An annealing process that could bypass this downside would therefore be of great interest. In this work, a short-time furnace annealing of a SiGe/TiO2 system is applied to obtain SiGe nanoparticles without formation of the undesired SiO2 layer between the dielectric matrix (TiO2) and SiGe. The structures were prepared by depositing alternate layers of TiO2 and SiGe films, using direct-current magnetron sputtering technique. A wide range spectral response with a response-threshold up to ∼1300 nm was obtained, accompanied with an increase in photo-response of more than two-orders of magnitude. Scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray spectroscopy and grazing incidence x-ray diffraction were used to analyze the morphological changes in respective structures. Photoconductive properties were studied by measuring photocurrent spectra using applied dc-voltages at various temperatures.

Effects of Platelet Rich Fibrin on Full Thickness Skin Grafts in the Rat Model-Planimetry Results.

Platelets play a crucial role in wound healing as they are reservoirs of growth factors and cytokines which play a fundamental role in homeostasis and tissue remodeling. Recently, fields such as dermatology and plastic and reconstructive surgery have become interested in the tissue regenerative properties of these compounds, especially since it promotes wound healing, improves scar outcomes and has rejuvenating effects on the skin and other tissues. We evaluated the effects of Platelet Rich Fibrin (PRF) in full thickness skin graft healing. Our study included 40 male Wistar rats. Skin grafts were assessed macroscopically using planimetry. The full thickness skin grafts in the test group, displayed a lower necrosis rate compared to the control group. Our study displays the potential benefits of using Platelet Rich compounds to facilitate wound healing and integration of full thickness skin grafts.

Palatal Reconstruction after Major Surgical Excision.

Oncological excision surgery in the oral and maxillofacial area amputates important structures or open cavities (sinus, nose, mouth) which are usually "closed". The disappearance of an eye, tongue, soft palate or cheek, raises serious issues regarding the resumption of partial or total functions of that region, in terms of social reintegration of the patient. In the cephalic extremity, the reconstruction material is limited, so specialists resort to resources located away from the defect to achieve closure. The temporal flap isn't used very often, although this procedure has the advantages of a shorter time for surgery and for healing.

Dense Ge nanocrystals embedded in TiO2 with exponentially increased photoconduction by field effect.

Si and Ge nanocrystals in oxides are of a large interest for photo-effect applications due to the fine-tuning of the optical bandgap by quantum confinement in nanocrystals. In this work, dense Ge nanocrystals suitable for enhanced photoconduction were fabricated from 60% Ge in TiO2 amorphous layers by low temperature rapid thermal annealing at 550 °C. An exponential increase of the photocurrent with the applied voltage was observed in coplanar structure of Ge nanocrystals composite films deposited on oxidized Si wafers. The behaviour was explained by field effect control of the Fermi level at the Ge nanocrystals-TiO2 layer/substrate interfaces. The blue-shift of the absorption gap from bulk Ge value to 1.14 eV was evidenced in both photocurrent spectra and optical reflection-transmission experiments, in good agreement with quantum confinement induced bandgap broadening in Ge nanocrystal with sizes of about 5 nm as found from HRTEM and XRD investigations. A nonmonotonic spectral dependence of the refractive index is associated to the Ge nanocrystals formation. The nanocrystal morphology is also in good agreement with the Coulomb gap hopping mechanism of T-1/2 -type explaining the temperature dependence of the dark conduction.

A Rare Case of Upper Calf Swelling and Necrosis - The Morel-Lavallée Lesion.

A 31-year-old patient presented in the Emergency Department with a tibial fracture following a car accident that crushed the lower third of his thigh and the proximal and median part of his calf. Tibial fracture fixation with an intramedullary rod, was complicated by a Morel-Lavallée lesion. Sequential debridement procedures were performed with partially successful granulation tissue proliferation under NPWT (Negative-Pressure Wound Therapy). To further promote the already delaying granulation, plastic surgeons opted for PRP/PRF (Platelet Rich Plasma/Platelet Rich Fibrin) which allowed appropriate skin grafting. In our opinion, PRP/PRF should be considered as a viable adjuvant therapy to promote granulation.

Single layer of Ge quantum dots in HfO2 for floating gate memory capacitors.

High performance trilayer memory capacitors with a floating gate of a single layer of Ge quantum dots (QDs) in HfO2 were fabricated using magnetron sputtering followed by rapid thermal annealing (RTA). The layer sequence of the capacitors is gate HfO 2/floating gate of single layer of Ge QDs in HfO 2/tunnel HfO 2/p-Si wafers. Both Ge and HfO2 are nanostructured by RTA at moderate temperatures of 600-700 °C. By nanostructuring at 600 °C, the formation of a single layer of well separated Ge QDs with diameters of 2-3 nm at a density of 4-5 × 1015 m-2 is achieved in the floating gate (intermediate layer). The Ge QDs inside the intermediate layer are arranged in a single layer and are separated from each other by HfO2 nanocrystals (NCs) about 8 nm in diameter with a tetragonal/orthorhombic structure. The Ge QDs in the single layer are located at the crossing of the HfO2 NCs boundaries. In the intermediate layer, besides Ge QDs, a part of the Ge atoms is segregated by RTA at the HfO2 NCs boundaries, while another part of the Ge atoms is present inside the HfO2 lattice stabilizing the tetragonal/orthorhombic structure. The fabricated capacitors show a memory window of 3.8 ± 0.5 V and a capacitance-time characteristic with 14% capacitance decay in the first 3000-4000 s followed by a very slow capacitance decrease extrapolated to 50% after 10 years. This high performance is mainly due to the floating gate of a single layer of well separated Ge QDs in HfO2, distanced from the Si substrate by the tunnel oxide layer with a precise thickness.

Case Presentation of Soft Tissue Defect after Bimalleolar Fracture Osteosynthesis.

A 59-year-old patient presented in the ER with wound dehiscence and skin necrosis on the right ankle, with osteosynthesis implant visible, after open reduction and fixation with plate and screws, performed abroad, 16 days prior to the presentation, for a bimalleolar fracture. The patient was admitted to the plastic surgery department, where surgical debridement of the necrotic tissue was initially performed. Postoperatively, the patient was treated with Negative-pressure wound therapy (VAC dressing) and Platelet rich plasma (PRP) therapy. Upon obtaining granulation tissue without signs of infection, a sural fasciocutaneous flap was performed to cover the skin defect. Proper graft integration and healing was observed.

Quantification of liver fibrosis in chronic hepatitis B virus infection.

Chronic hepatitis B virus infection (HBV) is considered a global public issue with more than 78.000 people per year dying of its evolution. With liver transplantation as the only viable therapeutic option but only in end-stage disease, hepatitis B progression may generally be influenced by various factors. Assessing fibrosis stage plays an important part in future decisions on the patients' wealth with available antiviral agents capable of preventing fibrosis passing to an end-stage liver disease. Several methods have been taken into consideration as an alternative for HBV quantification status, such as imaging techniques and serum based biomarkers. Magnetic resonance imaging, ultrasound, and elastography are considered non-invasive imaging techniques frequently used to quantify disease progression as well as patients future prognostic. Consequently, both direct and indirect biomarkers have been studied for differentiating between fibrosis stages. This paper reviews the current standings in HBV non-invasive liver fibrosis quantification, presenting the prognostic factors and available assessment procedures that might eventually replace liver biopsy.

Wireless Capsule Endoscopy in Correlation with Software Application in Gastrointestinal Diseases.

Wireless capsule endoscopy is one of the most recent investigation techniques of gastrointestinal pathology. Unlike conventional upper and lower endoscopy, it has the advantages of being a noninvasive and painless procedure. One of the capsule endoscopy disadvantages is represented by the necessary time to analyze the video frames obtained. Software applications proposed in this purpose could offer support in the images evaluation. Different algorithms have been described in the literature, but further research is needed to establish the practical value of computer vision tools in gastroenterology.

The Role of Podoplanin in the Lymphangiogenesis of Oral Squamous Carcinomas.

Oral squamous cells carcinoma (OSCC) mortality rate ranges between 29-40/100,000 inhabitants. Regional lymph node metastases occur in 30-40% cases and are associated with unfavorable prognosis and decreased survival. Recentely it was suggested that the tumor-associated lymphatic vessels formation plays an active role in metastasis proces of several human malignancies, including OSCC. In the present study we investigated comparatively podoplanin immunoexpression in OSCC in both the tumor cells and lymphatic vessels reported to clinicopathological prognostic parameters. Material and methods The study included a total of 25 cases of OSCC. We investigated clinico-pathological parameters as age, gender, tumor site, and degree of differentiation, size and depth of invasion (pT), lymph node status (pN). Histologic classification was done according to the WHO criteria. For immunohistochemical (IHC) analysis we used podoplanin (Dako, clone D2-40). As visualization system it was used LSAB2 (Dako, Redox, Romania, code K0675) and chromogen DAB (Dako, Redox, Romania, code K3468). Negative controls were obtained by omitting the primary antibodies. IHC quantification was done intensity score and by lymphatic microdensity (LVD), intratumoral and on the advancing edge. For the statistical analysis we used Student's t-tests, ANOVA, chi square and Pearson, using SPSS 10 software. Results Podoplanin immunoexpression in tumor parenchyma presented with an average of 43%, varying intensity. We found a higher intensity in weak and moderately differentiated SCC then in well differentiated ones and no difference intratumoral aand advancing edge. In relation to the degree of tumor differentiation the mean LVD D2-40 was higher in the advancing edge. SCC who presented lymph node metastasis mean values for LVD D2-4 was higher then at advancing edge and higher than those of non-metastatic carcinomas. Conclusions Podoplanin immunoexpresion suggests the involvement both in tumor growth and the acquisition of an lymphangiogenic phenotype invasive by autocrine mechanisms.

NOD2 Arg702Trp Polymorphism in Romanian Patients with Gastric Cancer.

PURPOSE: Our study aimed to assess a possible correlation between NOD2 Arg702Trp (rs2066844) polymorphism and gastric cancer risk in a Romanian population. MATERIAL/METHODS: A total of 322 subjects (72 patients with gastric adenocarcinoma and 250 healthy controls) were included. Genomic DNA was extracted from blood leukocytes and NOD2 Arg702Trp polymorphism was genotyped by Real-Time PCR using specific TaqMan probes. RESULTS: No statistically significant difference was observed between gastric cancer patients and controls when we compared one genotype with other genotype (the CC genotype serves as reference) (OR 0.45, 95% CI: 0.10 - 2.05) or when we compared allele frequencies (the C allele serves as reference) (OR 0.46, 95% CI: 0.11 - 2.04). We examined separately the association of this polymorphism with tumor site and histologic type and no correlation was found. CONCLUSION: NOD2 Arg702Trp polymorphism is not associated with gastric cancer risk and further investigations are needed to elucidate the contribution of NOD2 gene in gastric carcinogenesis.

Cutaneous leiomyosarcoma - Case report.

Cutaneous leiomyosarcoma (CLM) is a very rare smooth muscle tumor arising from the dermis or subcutaneous tissue in the skin. Superficial leiomyosarcoma originates in the superficial dermis or subcutaneous tissue and represents about 3% of the soft tissue sarcomas. CLM presents in persons of all ages but with a peak between 60-70 years old. It may also occur anywhere on the body; the existing cases reported it on the face and trunk. The clinic of leiomyosarcoma consists in a firm dermal nodule, which can be painful, pruritic or paresthestic. The tumor is of 1-3 cm in diameter and can often be seen as a solitary formation. We report one case of a cutaneous leiomyosarcoma arising in the chest region of a 79- year-old male. Leiomyosarcoma is a rare entity whose clinical presentation may appear nonspecific, making diagnosis difficult. Primary tumor excision with wide oncological safety margins is considered, when suitable case, the most appropriate method. Other therapeutic methods, such as radio- or chemotherapy are described as without significant benefits. Despite the claims of radical surgical treatment, due to recurrence rates, the prognosis remains poor. We recommend long-term follow-up of patients to capture a subsequent malignant disease progression.

Bullous pemphigoid associated with psoriasis, breast cancer and Parkinson's disease.

Bullous pemphigoid (BP) and psoriasis vulgaris represent two clinically well characterized, inflammatory, chronic skin diseases. A 62 years old female patient, from rural areas, was admitted for the presence of erythematous plaques covered by large tense blisters with clear fluid, located symmetrically on the anterior part of the upper limbs, the trunk, the neck and the lower limbs. Also the lesions were intense itching. Lesions occurred three days before presentation at the clinic. Medical history revealed psoriasis diagnosed 28 years ago, breast cancer treated with surgery, radio and chemotherapy three years ago and Parkinson's disease diagnosed 3 weeks prior to presentation to the dermatology clinic. Histopathology examination revealed: atrophic epidermis with subepidermal presence of a blister containing numerous eosinophils and neutrophils. In the papillary dermis neutrophils and eosinophils predominantly vascular. Bullous pemphigoid has multiple etiology. Bullous pemphigoid is an autoimmune subepidermal bullous dermatosis which may be associated with psoriasis. Medical literature and cases reported in dermatology journals claim that bullous pemphigoid is often associated with psoriasis, though the immunogenetical and immunopathologycal mecanismes are still not known. Our patient has three different diseases but their etiology and pathogenesis can interfere.

Role of MRI in the diagnosis and evaluation of cavernous hemangioma of the arm.

Sinusoidal hemangioma is a rare type of cavernous hemangioma with different clinico-pathological aspects. They are usually localized in the extremities with interest in the subcutaneous layer. The new imaging techniques play an important role in diagnosis, evaluation and follow-up of these types of tumors. We describe the case of a 21-year-old patient, four times operated for a recurrent soft tissue tumor, located intramuscularly in the distal third of the upper limb. Plain X-ray and computer tomography (CT) showed a nonspecific mass with calcification. The MRI (magnetic resonance imaging) exam demonstrated a lobulated heterogeneous signal tumor mass in the biceps brachial muscles, with high signal intensity on T2 weighted images and intermediate signal on T1 weighted images. MRI accurately assessed the extent of the tumor and evaluated the recurrence. MRI imagings combined with contrast-enhanced sequences were used to classify the lesions in low flow vascular disorders. CT angiography with multiplanar reconstructions (MPR), maximum intensity projections (MIP) and volume-rendered reconstructions (VR) was useful in confirming the venous origin of the tumor.

The economic analysis of two treatment procedures for incisional hernias - alloplastic versus tissular.

Incisional hernias are a common complication of abdominal surgery. Research shows that their incidence reaches 10%-11% of the total number of patients subject to laparotomy. Recurrent hernias are the main complication of eventrations and its rate ranges from 5 to 54%, depending on both the surgical procedure used and the follow-up methods. The goal of this study is the comparative cost analysis of two procedures used in the treatment of event rations, tissular versus alloplastic, the former, leading very often to recurrence requiring a new surgical intervention. The analysis comprised 156 cases of surgeries performed for incisional hernia in 2007 in the clinic of Surgery III, SUUB (Bucharest University Emergency Hospital). Tissular procedures were used in 42 cases and prosthetic procedures in 114 cases. The medium-term postoperative follow-up has revealed 17 relapses (40.4%) in the tissular batch and no relapse in the batch where parietal prosthesis was used. If the short-term costs of the tissular procedures are low as compared with the prosthetic procedures, on the medium-term the costs increase by 24.35% due to the high rate of relapses of tissular procedures. Therefore, the tissular procedure must be abandoned due to the high rate of relapse, as this drives additional costs required for the alloplastic repair of the abdominal parietal defects in a subsequent surgical intervention.

Wound infections with multi-drug resistant bacteria.

INTRODUCTION: Wound infections remain a public health problem, despite the progress made on improving surgical techniques and antibiotic prophylaxis application. Misuse of antibiotics to prevent bacterial infections leads to increased bacterial resistance and their dissemination. MATERIAL AND METHODS: The study refers to 470 samples taken from wound infections of which only multi-drug resistant strains were selected for study, using two special culture mediums (Metistaph-2 for methicillin-resistant staphylococci and ESBLs-Agar for extended-spectrum betalactamases secreting bacteria). Sensitivity of these strains was tested using the diffusion method. RESULTS: Of all studied samples, a rate of 27.6 bacterial strains showed multi-drug resistance. Among them stood primarily Staphylococcus aureus; both MRSA strains and ESBL Gram negative bacteria studied showed high resistance to aminoglycosides, quinolones, third generation cephalosporins and low to fourth generation cephalosporins. No vancomycin resitant nor vancomycin-intermediate Staphylococcus aureus strains were isolated. CONCLUSIONS: Knowing the antibiotic resistance is very useful in antibiotic "cycling"application, avoiding this way the emergence of increased resistant strains.

Pure pectus carinatum (not associated with pectus excavatum) solved by MIRPC (minimally invasive repair of pectus carinatum) associated with bilateral mamarian hypoplasia solved by bilateral breast implants.

We present the case of a young 24-year-old woman with an important but symmetrical pectus carinatum, not associated with pectus excavatum, without cardiorespiratory symptoms but with significant psychosocial implications for the patient, solved by the minimally invasive technique described by Abramson(reversed Nuss procedure) - MIRPC (Minimally invasive Repair of Pectus carinatum). The sternal malformation was associated with bilateral mammary hypoplasia, solved by bilateral breast implants 10 months later. The evolution was favorable and the aesthetic result was satisfactory for the patient.