Ga metal nanoparticle-GaAs quantum molecule complexes for terahertz generation.

A hybrid metal-semiconductor nanosystem for the generation of THz radiation, based on the fabrication of GaAs quantum molecules-Ga metal nanoparticles complexes through a self assembly approach, is proposed. The role of the growth parameters, the substrate temperature, the Ga and As flux during the quantum dot molecule (QDM) fabrication and the metal nanoparticle alignment are discussed. The tuning of the relative positioning of QDMs and metal nanoparticles is obtained through the careful control of Ga droplet nucleation sites via Ga surface diffusion. The electronic structure of a typical QDM was evaluated on the base of the morphological characterizations performed by atomic force microscopy and cross sectional scanning electron microscopy, and the predicted results confirmed by micro-photoluminescence experiments, showing that the Ga metal nanoparticle-GaAs quantum molecule complexes are suitable for terahertz generation from intraband transition.

A cytoreductiv sebészet és hyperthermiás intraperitonealis chemotherapia szerepe a peritoneum malignus elváltozásainak kezelésében.

Peritoneal carcinosis is considered to be a lethal disease with a very poor prognosis, however cytoreducticve surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) could represent a significant step forward in the therapy of peritoneal cranosis. In contrast to traditional surgical procedures and intravenous chemotherapy, which are moderately effective, CRS and HIPEC are new, personalised interventions, which can extend the lifespan of the patients in the majority of the cases. Moreover, there is a possibility to carry out definitive, curative therapy in a well-selected group of cases. The aim of this article is to review the relevant literature on these procedures, which are novelties in Hungary, and to include our own experience, too.

[Splenic vein aneurysm -- a case report]. / Lépvéna-aneurysma operált esete.

Authors report a very rare case of splenic vein aneurysm in a 34-year-old female patient. She underwent investigation for upper abdominal pain which was not related to eating. Diagnostic workup revealed a thin wall saccular splenic vein aneurysm of 40 mm in diameter which caused an indentation of the posterior wall of the pancreas. She underwent surgery, a tangential resection was carried out preserving the continuity of the splenic vein and spleen. The patient had an uneventful postoperative course and she was discharged on the 5th postoperative day.

[Benign multicystic peritoneal mesothelioma]. / Benignus multicysticus peritonealis mesothelioma.

Benign multicystic peritoneal mesothelioma is a rare benign tumor originating from the peritoneum, affecting mostly young, fertile women. Its presentation is non-specific, thus the final diagnosis is made after the histological examination. A young female patient presented with incarcerated inguinal hernia of which an emergency surgery was performed. During the operation a cystic mass neighboring the round ligament in the canal of Nuck was removed. No inguinal hernia was found. The histological examination confirmed the diagnosis of benign multicystic mesothelioma. The patient was referred to a center performing hyperthermic intraperitoneal chemotherapy, where laparoscopic exploration was performed. The second surgery revealed no residual tumor or any other pathology. A 41-year-old male patient, 4 years before presenting at our ward, had an elective umbilical hernia repair surgery. During the operation 2 cm big cystic mass was removed from the peritoneum, and the histological examination revealed benign multicystic mesothelioma. In 2018, acute surgery was performed due to a periappendicular abscess, while during the surgery a multicystic mass situated on the distal end of the appendix was also removed. The pathological finding confirmed the recurrence of the first tumor. The radiological examination did not find any signs of residual tumor mass anywhere else. The chances of malignant transformation in cases of benign multicystic peritoneal mesothelioma are low. The suggested treatment is en bloc surgical removal of the mass, however, in these cases recurrence is still 50%. If during follow-ups the recurrence of the tumor is found, a total peritonectomy or hyperthermic intraperitoneal chemotherapy is advisable. Orv Hetil. 2019; 160(21): 839-843.

GaAs epilayers grown on patterned (001) silicon substrates via suspended Ge layers.

We demonstrate the growth of low density anti-phase boundaries, crack-free GaAs epilayers, by Molecular Beam Epitaxy on silicon (001) substrates. The method relies on the deposition of thick GaAs on a suspended Ge buffer realized on top of deeply patterned Si substrates by means of a three-temperature procedure for the growth. This approach allows to suppress, at the same time, both threading dislocations and thermal strain in the epilayer and to remove anti-phase boundaries even in absence of substrate tilt. Photoluminescence measurements show the good uniformity and the high optical quality of AlGaAs/GaAs quantum well structures realized on top of such GaAs layer.

[Metabolic imaging--PET, PET/CT--in oncologic surgery]. / A metabolikus képalkotás - PET, PET/CT - onkosebészeti vonatkozásai.

The availability of PET/CT examinations in Hungary has significantly improved in the past few years. In the three Hungarian centres approximately 10,000 examinations can be performed yearly, which are financed by the national healthcare system. The PET/CT technique using FDG has become an efficient tumour diagnostic method due to its outstanding sensitivity and specificity. Similarly to other medical imaging techniques, PET/CT is a useful and cost-beneficial diagnostic modality in the hand of those clinicians, who clearly know its advantages and limitations. In the present paper the most frequent indications of PET/CT examinations are reviewed, with special attention to cases relevant to the everyday surgical practice. The applicability of this technique is also considered.

Silica-supported Au nanoparticles decorated by TiO2: formation, morphology, and CO oxidation activity.

Au-TiO(2) interface on silica support was aimed to be produced in a controlled way by use of Au hydrosol. In method A, the Au colloids were modified by hydrolysis of the water-soluble Ti(IV) bis(ammoniumlactato)dihydroxide (TALH) precursor and then adsorbed on Aerosil SiO(2) surface. In method B, Au sol was first deposited onto the SiO(2) surface and then TALH was adsorbed on it. Regular and high-resolution transmission electron microscopy (TEM and HRTEM) and energy dispersive spectrometry (EDS) analysis allowed us to conclude that, in method A, gold particles were able to retain the precursor of TiO(2) at 1.5 wt % TiO(2) loading, but at 4 wt % TiO(2) content the promoter oxide appeared over the silica surface as well. With method B, titania was detected on silica at each TiO(2) concentration. In Au-TiO(2)/SiO(2) samples, the stability of Au particles against sintering was much higher than in Au/TiO(2). The formation of an active Au-TiO(2) perimeter was proven by the greatly increased CO oxidation activity compared to that of the reference Au/SiO(2).

[Stromal tumor of the stomach causing life-threatening arterial bleeding]. / A gyomor életveszélyes arteriás vérzést okozó stromalis tumora.

Stromal tumors of the gastrointestinal tract are rare mesenchymal neoplasms. The majority of them are appearing in the stomach: their quite common first manifestation is bleeding. The authors report a case of polypoid gastric GIST causing severe bleeding which needed urgent surgical intervention and partial resection of the stomach. Although histological analysis of the tumor revealed low proliferation rate, the urgent operation did not result in a complete eradication of the neoplasm, thereby our patient needs further follow-up and treatment.

Diurnal blood pressure pattern may predict the increase of urinary albumin excretion in normotensive normoalbuminuric type 1 diabetes mellitus patients.

To characterise the relationship between diurnal blood pressure and the subsequent increase of urinary albumin excretion (UAE) in normotensive normoalbuminuric type 1 diabetic patients, ambulatory blood pressure monitoring (ABPM) was performed in 53 patients, who were then followed for 5 years. Albumin excretion rate changed from 12.4 (8.9-17.2) to 29.3 (15.2-47.0) mg/day. Macroalbuminuria developed in 2 (3.8%), microalbuminuria in 22 (41.5%) patients, 29 (54.7%) remained normoalbuminuric. Night-time diastolic blood pressure was significantly higher (64.3+/-6.5 vs. 60.9+/-5.5 mmHg, P<0.05), diastolic diurnal index significantly lower (15.5+/-9.7 vs. 22.3+/-6.2%, P<0.01) in patients who later progressed to micro- or macroalbuminuria. Diastolic diurnal index (r=-0.40; P<0.01) and nocturnal diastolic pressure (r=0.35; P<0.01) were correlated to the change in albumin excretion. In a multivariate analysis model with the change of albumin excretion as dependent, and means and diurnal indices of systolic and diastolic blood pressure, baseline UAE, cholesterol, triglycerides, HbA1c and retinopathy as independent parameters (r=0.68; P=0.001), diurnal index for diastolic blood pressure (beta=-0.30; r=0.013), baseline HbA1c (beta=0.32; P=0.010) and retinopathy (beta=0.44; P=0.001) were significant independent correlates. We conclude that the relative increase of nocturnal blood pressure is associated with the subsequent increase of albuminuria, which in turn is predictive of overt diabetic nephropathy.

Urinary albumin excretion is correlated to fibrinogen levels and protein S activity in patients with type 1 diabetes mellitus without overt diabetic nephropathy.

The aim of the study was to test the hypothesis that in diabetic patients without overt nephropathy there may be a correlation between the activity of natural anticoagulant proteins and glomerular dysfunction. Assays for functional activity of proteins S and C, measurements of urinary albumin excretion, lipid parameters and haemoglobin A1c were performed in 91 patients with type 1 diabetes mellitus and 85 patients with type 2. Patients with type 1 diabetes and microalbuminuria had significantly higher mean age (44.1 +/- 10.9 vs. 37.9 +/- 12.7 years; p<0.05), fibrinogen level (3.75 +/- 1.0 vs. 3.21 +/- 0.8 g/l; p<0.01), protein S activity (92.3 +/- 17.6 vs. 84.5 +/- 15.5%; p<0.05) and higher prevalence of retinopathy (p<0.01) and macrovascular disease (p<0.01) than those with normoalbuminuria. Albumin excretion was significantly correlated to age (r=0.25, p<0.05), fibrinogen level (r=0.39, p<0.01), protein S activity (r=0.27; p<0.05), total cholesterol (r=0.23; p<0.05), apoprotein B (r=0.22; p<0.05), retinopathy (r=0.33; p<0.01) and macrovascular disease (r=0.33; p<0.01). Patients with type 2 diabetes mellitus and microalbuminuria had significantly higher apoprotein B levels (1.17 +/- 0.3 vs. 1.06 +/- 1.2 mg/dl; p<0.05) than those with normoalbuminuria, and apoprotein B was significantly correlated to albumin excretion (r=0.22; p<0.05). In a multivariate model of type 1 diabetes mellitus with fibrinogen, protein S and C activity, cholesterol, triglycerides, haemoglobin A1c, retinopathy, and macrovascular disease as independent parameters (r=0.53; p<0.003), there was significant independent correlation of fibrinogen (beta=0.28; p<0.01), protein S activity (beta=0.27; p<0.05) and retinopathy (beta=0.21; p<0.01) with albumin excretion. We conclude that in type 1 diabetes, relative elevation of fibrinogen level and protein S activity appear in the early stages of development of diabetic nephropathy, and may be related to the pathogenesis of diabetic kidney disease.

Sealing of hard CrN and DLC coatings with atomic layer deposition.

Atomic layer deposition (ALD) is a thin film deposition technique that is based on alternating and saturating surface reactions of two or more gaseous precursors. The excellent conformality of ALD thin films can be exploited for sealing defects in coatings made by other techniques. Here the corrosion protection properties of hard CrN and diamond-like carbon (DLC) coatings on low alloy steel were improved by ALD sealing with 50 nm thick layers consisting of Al2O3 and Ta2O5 nanolaminates or mixtures. In cross sectional images the ALD layers were found to follow the surface morphology of the CrN coatings uniformly. Furthermore, ALD growth into the pinholes of the CrN coating was verified. In electrochemical measurements the ALD sealing was found to decrease the current density of the CrN coated steel by over 2 orders of magnitude. The neutral salt spray (NSS) durability was also improved: on the best samples the appearance of corrosion spots was delayed from 2 to 168 h. On DLC coatings the adhesion of the ALD sealing layers was weaker, but still clear improvement in NSS durability was achieved indicating sealing of the pinholes.

Gastric bleeding in a patient with rheumatoid arthritis complicated by immune thrombocytopenic purpura.

Rheumatoid arthritis, in common with other systemic autoimmune diseases, can involve several other organs presenting with complex immunological manifestations. Immune thrombocytopenic purpura caused by an autoimmune reaction against platelets is an infrequent haematological complications. A female patient with rheumatoid arthritis rapidly developed extremely severe immune thrombocytopenic purpura upon suspending oral corticosteroid therapy. Besides the involvement of the mucosa of the coecum, ascending colon and the gastric antrum, the situation was further complicated by bleeding of a gastric polyp, at the nadir of the thrombocytopenic crisis. The bleeding was managed by endoscopic intervention and platelet count recovered upon high dose corticosteroid treatment within a couple of days.