Alternate monolayers of CdSe nanocrystals and perylene tetracarboxylate: quantum dot hypersensitization for dye-sensitized solar cells.

Mono- and multilayers from CdSe nanocrystal dispersion and perylene tetracarboxylate solution are reported for the first time. The layers were investigated by UV-visible spectroscopy, cyclic voltammetry, photoconductivity, and photoelectrochemical techniques. The n-type organic semiconductor gives enhanced photoconductivity to the CdSe-NC multilayer structure. The photoactive perylene monolayer acts also as hypersensitizer of CdSe-NC structures. The perylene-modified CdSe-NC monolayer on indium tin oxide (ITO) electrode in a three-electrode photoelectrochemical cell upon illumination in the presence of oxygen generates an intense steady photocurrent as high as 10-20 times that expected from the individual contributions of perylene and CdSe-NCs. The hypersensitization mechanism is discussed on the basis of the energy level diagram of the components.

The detection of a population of submillimeter-bright, strongly lensed galaxies.

Gravitational lensing is a powerful astrophysical and cosmological probe and is particularly valuable at submillimeter wavelengths for the study of the statistical and individual properties of dusty star-forming galaxies. However, the identification of gravitational lenses is often time-intensive, involving the sifting of large volumes of imaging or spectroscopic data to find few candidates. We used early data from the Herschel Astrophysical Terahertz Large Area Survey to demonstrate that wide-area submillimeter surveys can simply and easily detect strong gravitational lensing events, with close to 100% efficiency.

Immunohistochemical expression of fatty acid synthase, Ki-67 and p53 in squamous cell carcinomas of the larynx.

Fatty acid synthase (FAS) is a recently discovered molecule involved in the energy supply to normal cells. FAS is overexpressed in neoplastic tissues because of their increased energy needs. We explored the immunohistochemical expression of FAS, Ki-67 and p53 in squamous cell carcinomas (SCC) of the larynx and their association with clinicopathological features and outcome. Specimens from 43 patients with SCC were evaluated. Statistical analysis revealed an association between poorly differentiated laryngeal carcinomas and FAS expression (p<0.005) and between FAS and Ki-67 overexpression (p<0.001). Finally, FAS expression was associated with overall survival (p<0.001). We suggest that FAS is a powerful prognostic indicator whose strength can be enhanced when it is evaluated together with clinicopathological data and Ki-67 expression.

[Parietal recurrence after resection of colorectal carcinoma]. / La recidiva parietale dopo chirurgia resettiva del carcinoma colo-rettale.

The incidence of local recurrence of colo-rectal carcinoma is about 15-50%. The parietal recurrence is localized next parietal incision and its incidence is rare (0.2-2%). The treatment of this lesion is based on palliative radiotherapy and chemotherapy; the surgical treatment is based on parietal resection. The Authors describe a case of parietal recurrence after colo-rectal adenocarcinoma and conclude that the prognosis of this lesions is infaust.

[Hypocobaltemia in chronic obstructive arteriopathy. Physiopathologic and therapeutic importance]. / L'ipocobaltemia nelle arteriopatie croniche ostruttive. Suo significato fisiopatologico e terapeutico.

The role of some so-called primary and secondary (or oligo-elements) elements in the physiopathology of the cardiocirculatory system has been well known from a number of years and they have been regularly included in the treatment protocols. Some, including K, Ca, Mg and Zn, are extremely well known and widely used in clinical practice. Recently, however, a growing number of studies have focused on the biological importance of other oligo-elements in the pathogenetic mechanisms of atherogenesis and its clinical manifestations. This study aimed to verify the exact role of free cobalt in the physiopathology of the chronic obstructive arterial diseases (COAD). A total of 80 patients affected by 2nd stage COAD were examined and the levels of some oligo-elements, including Co, were assayed. Constantly low levels were found (85% of cases) in relation to other oligo-elements studied (Cu, Zn, Mg, Ca). This findings is particularly interesting since it confirms the biochemical hypothesis of atherosclerosis according to which parietal damage plays a central role in the pathogenetic mechanism. Some enzymatic deficiencies, which lead to changes in membrane stability at the level of the endothelial cells, are closely related to the presence of tissutal and humoral peroxidation products. These peroxides (lipid peroxides), which are formed following the interaction of fatty acids with oxygen free radicals, have been identified by a number of studies as being responsible for endothelial damage. Several authors have shown that lipid peroxidation is involved in the atherogenic process through several mechanisms entailing monocytic activity and reduced prostacyclin (PG2) synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cemented hip prostheses: modular screw system.

The long-term results of 21 patients treated with modular screw cementless hip prostheses are reported. An examination of periprosthetic osteogenesis and function evaluated by gait analysis revealed good incorporation of the prosthesis and good clinical results in all of the cases studied.

"Cyto-assisted", ultrasound-guided biopsy in the diagnosis of focal disease of the abdomen.

From May 1988 to June 1990, 260 patients with abdominal focal disease underwent ultrasonically guided percutaneous fine needle biopsy. The technique of so-called "FNAB-CYT" is described. The procedure entailed very few complications: the mortality rate was 0% and the morbidity rate was 1.5%. The specificity of the technique was 100%, and sensitivity was 93.43%. False-negative diagnoses were made in 8 cases, and in 5 patients the cytologic diagnoses were uncertain. There were no false-positives. The possibility of an immediate control of the collected material by the pathologist avoids the risk of inadequate samples and reduces the number of biopsies for the patient. Comparison among diagnoses on rapid and definitive preparations and histologic ones was carried out to evaluate the diagnostic efficiency of the cytologic procedure. In our experience, a rapid staining of the smears allowed a correct cytologic diagnosis in 87.7% of the cases within approximately 5 min of the biopsy. On the basis of our experience, the authors recommend FNAB-CYT as a routine first-level (less invasive) procedure for diagnosis of abdominal focal disease.

[Changes in blood Zn, Se, Cd, Pb during therapeutic abstinence from alcohol in 101 cases of alcoholism]. / Variazioni ematiche di Zn, Se, Cd, Pb durante astinenza alcolica terapeutica in 101 casi di alcolismo.

The patients were subdivided into 3 groups, in accordance with clinical, echographic, laboratory and laparoscopy criteria: without liver disease, with liver disease and with alcoholic cirrhosis. In alcoholics with liver disease (with or without cirrhosis), we found a constant significant decrease in lead during abstinence, while in patients with cirrhosis zinc has a significant increase. Always lower to normal the blood selenium. The cadmium in the serum increases also after a month.

[Operations for limb salvage in vascular surgery]. / Gli interventi di salvataggio degli arti in chirurgia vascolare.

Direct revascularization which involve the femoro-popliteo-tibial district is called "limbs salvage" surgery. Such operations are performed in the arteriopathic patient in order to avoid ulcers and distal necrosis, whose natural evolution, without an adequate treatment, leads to amputation. One of the distal by-pass techniques is obtained by using in situ saphenous vein. The Authors report their experience with 281 patients who underwent direct revascularization surgery (by-pass), discussing technique and results.

Prevention of pulmonary complications by 6-methylprednisolone in major abdominal surgery.

Methylprednisolone sodium succinate (MPSS) was compared in a randomized, double blind study to placebo in the prevention of respiratory complications in patients submitted to abdominal (vascular, pancreatic or hepatic) surgery. Two out of 42 (4.8%) patients treated with MPSS and 9 patients out of 40 (22.5%) who received placebo experienced a pulmonary complication (p less than 0.05) The results indicate that methylprednisolone could prevent the onset of respiratory complications in patients undergoing major abdominal surgery.

Postoperative gastric complications in vascular patients.

Although there is no etiopathogenetic correlation between arterial diseases and gastroduodenal ulcer, a chronic gastric disease can increase postoperative morbidity and mortality, in patients with arterial diseases. Furthermore, postoperative complications due to the development of acute hemorrhagic gastritis are frequent and dangerous, even in patients without any pre-existing gastric pathology. The experience of our Department in this field is reported here, and the risk and severity of hemorrhagic complications after administration of prophylaxis in patients with arterial diseases and gastroduodenal ulcer are evaluated.

Percutaneous splenic artery occlusion for portal hypertension. A new mechanical technique for hypersplenism.

We studied 16 patients with hypersplenism, splenomegaly, and moderate nonbleeding portal hypertension with the purpose of discovering a hyperdynamic component associated with splenomegaly. We treated the patients' splenic hyperdynamic component and hypersplenism with a splenectomy. We measured wedge hepatic vein pressure (WHVP) before and after superior mesenteric artery occlusion by a balloon catheter, and after splenic artery (SA) occlusion by a balloon catheter. In 11 patients, following SA temporary occlusion an average WHVP reduction of 10.4 cm saline was obtained, and SA occlusion by Gianturco's coils was performed to obtain a gradual and segmentary occlusion. No colliquative phenomena were observed, and a stable decrease of WHVP with a marked improvement of peripheral cytopenia was obtained.