Measuring thermal conductivity of thin films by Scanning Thermal Microscopy combined with thermal spreading resistance analysis.

While measuring the thermal properties of a thin film, one of the most often encountered problems is the influence of the substrate thermal properties on measured signal and the need for its separation. In this work an approach for determining the thermal conductivity κ of a thin layer is presented. It bases on Scanning Thermal Microscopy (SThM) measurement combined with thermal spreading resistance analysis for a system consisting of a single layer on a substrate. Presented approach allows to take into account the influence of the substrate thermal properties on SThM signal and to estimate the true value of a thin film κ. It is based on analytical solution of the problem being a function of dimensionless parameters and requires numerical solution of relatively simple integral equation. As the analysis utilizes a solution in dimensionless parameters it can be used for any substrate-layer system. As an example, the method was applied for determination of the thermal conductivities of 4 different thin layers of thicknesses from 12 to 100nm. The impact of model parameters on the uncertainty of the estimated final κ value was analyzed.

A correlation between the heterogeneity of hypervariable region 1 of E2 glycoprotein of Hepatitis C virus (HCV) and HCV antibody profile: a case study.

A correlation between the heterogeneity of hypervariable region 1 (HVR1) of E2 glycoprotein (gp) and Hepatitis C virus (HCV) antibody profile was investigated. Of 6 patients studied two were in acute phase, two in chronic phase and two showed signs of long-time HCV infection, i.e. liver cirrhosis. All the patients exhibited a vigorous antibody response to viral proteins C, NS3, NS4 and NS5. An antibody response to HVR1 of E2 was found in one patient in acute phase and in one or two patients in chronic phase. Such a response was not found in the two patients with liver cirrhosis. Single-stranded conformation polymorphism (SSCP) and sequence analyses of HVR1 of E2 showed the lowest HVR1 heterogeneity in patients in acute phase and the highest one in those in chronic phase, while the long-time carriers of the virus showed an intermediate heterogeneity. This may reflect a specific interplay between the virus and immune system. The HVR1 heterogeneity may rise in the course of infection as a means of evading the immune pressure. Then, when an organism is unable to clear the virus, because the responses to HVR1 epitopes are weakened or exhausted, a population of less heterogeneous HVR1 variants may be established.

[The comparison of dynamics in humoral responses in health personnel after vaccination against hepatitis B using Engerix B and Gen-H-B-vax]. / Porównanie dynamiki odpowiedzi humoralnej u pracowników sluzby zdrowia po szczepionkach przeciwko wirusowemu zapaleniu watroby typu B (Engerix B, Gen-H-B-Vax).

The dynamics of humoral response in two groups of health care workers vaccinated according to the schedule 0, 1, 6 months, using two different recombinant vaccines has been comprised. In the group of persons vaccinated with Engerix B, 63 completed the full cycle of vaccination. Protective titer of anti-HBs (> or = 10 IU/L) was obtained in 93.6% of vaccinated. In the group of persons vaccinated with Gen-H-B-Vax, 62 completed the full cycle of vaccination, and protective titer of anti-HBs amounted to 90.3% of vaccinated. The humoral response on the protective level in both groups was not statistically different. However, the percentage of the persons with very high anti-HBs titers (10,000 and more IU/L) was higher after Engerix B.

[Long term results of vaccination against viral hepatitis B using recombinant vaccine Engerix B]. / Odlegle wyniki szczepienia przeciwko wirusowemu zapaleniu watroby typu B przy uzyciu rekombinowanej szczepionki Engerix B.

Among nineteen persons vaccinated against hepatitis B (recombinant Engerix B vaccine) fifteen (80 per cent) have developed anti-HBs (investigated 30 days after the third doses) on the protective level (10 U/l). After three and a half year three of them lost antibodies, and four had anti-HBs at level below 100 U/l. All of them received a booster doses, which resulted in a very high anti-HBs level one month later. Four persons without anti-HBs after the basic vaccination received in turn two booster doses: at the 3rd and 46th month. Only one person of them have remained a non-responder. We suggest to control a level of anti-HBs one month after basic vaccination for individual determination of the term of booster dose.

[Post-transfusion viral hepatitis non-A, non-B; serologic analysis of hepatitis C infections]. / Potransfuzyjne wirusowe zapalenie watroby typu nie-A, nie-B; analiza serologiczna zakazen wywolanych wirusem C.

Twenty patient, multitransfused 52 to 113 days before development of acute non-A, non-B viral hepatitis, were studied. In all of them UBI-HCV and Liatek tests (Organon) were performed in second day of hospitalization, and were repeated after 3 and 6 months. In 17 cases (85%) viral hepatitis C were diagnosed. In another three patients, hepatitis was probably caused by unidentified, non-A, non-B, non-C virus. The most frequently observed type of reactivity was parallel appearance of anti-HCV to structural and non-structural antigens in Liatek test (from 35% in first, to 70.6% in last investigation). Several patterns of combinations of serologic reactivity were observed. The most frequent anti-HCV were antibodies against structural, and anti-NS4 antigens. Chronic hepatitis developed in 65% of patients with hepatitis C.

[Anti-HCV antibodies among hemodialysed and kidney-transplanted patients]. / Markery hepatitis C (anty-HCV) u chorych dializowanych i po przeszczepie nerek.

We have studied from two hemodialysed centers to determine the prevalence of hepatitis C virus infection in hemodialysis 142 patients and 147 renal-transplant patients. Serum samples were tested for antibody by "Ortho HCV 2.0 ELISA test System" second generation assay. Antibody to hepatitis C virus was detected in 81 (57.04%) and 85 (57.82%) patients respectively. Age-related differences were not clear, but significantly were noted in hemodialysis patients. Patients with a history blood transfusion in both groups tended to have significantly high anti-HCV positivity rate. There was a tendency for a longer duration of hemodialysis to coincide with higher positivity anti-HCV.

[Liatek HCV: the six-antigen test for confirmation of the presence of anti-HCV antibodies]. / Liatek HCV: szescioantygenowy test potwierdzenia przeciwcial anty-HCV.

Fifty eight anti-HCV repeatable positive (the UBI HCV EIA, Microelisa test Organon Teknika) blood donors were tested using LIATEK-HCV EIA (Organon Teknika). The test was constructed using synthetic polypeptides renders possible to conduct separate investigation antibodies against structural and nonstructural antigens of HCV. In 51/58 (88 per cent) cases was agreement of the results with the UBI test, in 3/58 (5.1 per cent) results were negative, and in 4/58 (6.9 per cent) undetermined. In 90 per cent of the seropositive reactivity developed with four to six antigens. The most frequent "serological pattern" was anti: NS4, C1, C2, C3, C4 (31 per cent) and anti: NS4, NS5, C1, C2, C3, C4 (23.5 per cent).

[Anti-HCV antibodies against the structural and nonstructural antigens of hepatitis C in people seropositive in the second generation test]. / Anty-HCV przeciwko antygenom strukturalnym i niestrukturalnym wirusa C zapalenia watroby u osób seropozytywnych w tescie II generacji.

Forty six anti-HCV repeatable positive (the 2nd generation Abbott EIA test) adults, among which 26 were blood donors and 19 were patients with chronic hepatitis, were tested using Abbott HCV EIA Supplemental Assay. The test renders possible to conduct separate investigation antibodies against structural and nonstructural antigens of HCV. In 44/45 (97.8 per cent) cases was an agreement of the results with the 2nd generation test. In the most of cases (80 per cent) both types of antibodies were present. However, in 20 per cent of blood donors the antibodies against structural HCV antigen were not present whereas all the chronic hepatitis patients had these type of antibodies.

[Humoral response in health service personnel after administration of hepatitis B vaccine Gen-H-B-Vax]. / Odpowiedz humoralna u pracowników sluzby zdrowia po szczepionce Gen-H-B-Vax przeciwsko wirusowemu zapaleniu watroby typu B.

Within the group of 260 members of medical staff, the presence of the HBV markers was found in 87 persons (33.5%). Vaccination, which was of a voluntary character, was initiated in the group of 75 persons according to the pattern of 0, 1, 6 months with the use of vaccine GenH-B-Vax (Merck Sharp Dohme-Chibret A. G.) was completed in 62 persons. Humoral response was investigated with quantitative measurement of anti-HBs 30 days after each doses of the vaccine. After three doses of vaccine a protective level of anti-HBs (greater than or equal to 10 IU/l) have been obtained in 90.3% of vaccinated. Humoral response was higher in the group of younger (below 35 years of life) employees. Investigated vaccine was highly immunogenic and was well tolerated.

[Use of the "Multitest-CMI" in the evaluation of cutaneous delayed hypersensitivity reaction to antigens in patients with chronic diseases of the liver]. / Zastosowanie "Multitestu-CMI" w ocenie skórnej odpowiedzi typu póznego na antygeny przypominajace u chorych z przewlekøymi chorobami watroby.

Delayed cutaneous hypersensitivity was assessed in 120 patients (among them 109 HBsAg positive), with chronic persistent hepatitis, chronic active hepatitis, and compensated as well as decompensated liver cirrhosis by simultaneous application of seven standardized antigens and negative control ("Multitest CMI"). In 21 patients, after 12-24 months the tests were repeated. The sum of indurations of all positive responses ("score") were calculated. Responsiveness measured as results below a normal values was related to the advancing of liver disease (from 13% in chronic persistent hepatitis up to 77% in compensated and 61% in decompensated liver cirrhosis). A comparative analysis (t-Student test) of the arithmetical means of the "scores" revealed statistically significant differences between results obtained in diagnostic groups. It was also dependent from the severity of liver disease. Patients with chronic persistent hepatitis (without specific treatment) and patients with chronic active hepatitis (treated using thymus extract, TFX - "Polfa") has showed an increased "score" values. In contrast to this group, all persons with liver cirrhosis without skin-responsiveness in the first and second tests (anergy) died at the period of 18 months. "Multitest CMI" can be of value in assessing of results of immunotherapy, as well as prognosis of the course of advanced liver disease.

[Spontaneous splenic rupture as a complication of infectious mononucleosis]. / Samoistne pekniecie sledziony w przebiegu mononukleozy zakaznej.

Spontaneous splenic rupture as a complication of infectious mononucleosis in 17-years old man was described. Clinical manifestations of infectious mononucleosis were typical without any sign of the splenic rupture. At the end of third week of the disease sonographic investigation revealed subcapsular hematoma of the spleen without overt rupture. The patient was observed. Five days later in the next sonographic investigation the second hematoma of the spleen appeared. Patient was treated underwent splenectomy and he remain alive and well. Authors suggest that in cases with subcapsular hematoma of the spleen splenectomy remains the treatment of choice. Mononucleosis patients with significant enlarged spleen should be observed very carefully. Authors propose control sonographic investigation in 3rd or 4th week of the disease in those cases.

[Humoral response in hepatitis C infections: types of anti-HCV and reactivity evaluated using BLOT-index]. / Odpowiedz humoralna w zakazeniach wirusem C zapalenia watroby; rodzaje anty-HCV i typy reaktywnosci oceniane wskaznikiem BLOT-indeks.

In this paper an attempt has been made at quantitative evaluation of reactivity of various types anti-HCV using proposed BLOT-index. We based our research on 20 patients diagnosed with hepatitis-C (clinical, biochemical, serological and enzymatical criteria--repeatedly positive results of second generation screening tests EIA ABBOTT HCV and UBI HCV Monoelisa Organon Teknika) who were anti-HCV determined at the beginning the acute phase and after 3 and 6 months. Multiantigen tests were used veryfying LIATEK-HCV 2 and LIATEK-HCV 3 Organon Teknika. Value of BLOT-index was algebraic sum of "pluses" for particular anti-HCV. Three models of dynamics of BLOT-index were observed: increase, plateau and decrease. Statistically significant differences between values of BLOT-index were shown at the beginning of the acute phase of hepatitis-C and after 6 months. There were no differences observed between convalescents and patients who developed chronic hepatitis-C (test t-Student's and f-Fisher's). Reactivity of anti-HCV, evaluated using BLOT-index, shown increasing trend, which is a dominant pattern, however quantitative and qualitative changes do not occur more frequently than every 6 months. The LIATEK-HCV 3 gives fewer undetermined reactions and detects anti-HCV earlier than a former generation of this test.

[Chylopericardium as a complication of mitral valve replacement]. / Chylopericardium--powiklanie po operacji wymiany zastawki mitralnej.

We demonstrate the case of 47 year old woman with chylopericardium after mitral valve replacement. By reason of heart tamponade she underwent surgical treatment resulted in complete relief of the pericardial effusion.

[Dilated cardiomyopathy in HIV infection]. / Kardiomiopatia rozstrzeniowa w przebiegu zakazenia HIV.

The HIV-positive patient with dilated cardiomyopathy was described. Possible causes of heart failure in HIV infection was discussed. To achieve subclinical heart failure diagnosis authors suggest to perform echocardiography as a routine procedure in HIV-positive patients with low CD4 lymphocytes count and who have been infected for long time or when their disease becomes more advanced.

[Effectiveness of antiviral treatment of patients with chronic hepatitis C (a Polish multicenter study)]. / Efektywnosc leczenia przeciwwirusowego przewleklego zapalenia watroby typu C (wieloosrodkowe badania pòlskie).

Interferon alpha (INF) is routine treatment in patients with chronic hepatitis C. Many controlled investigations were evaluated to establish the optimal schedule of treatment with sustained virological and biochemical response. Recently, multicentre meta-analyses suggest that combination therapy (INF + Ribavirin) was more effective than treatment with interferon alone. The aim of this study was to compare the efficacy of four schedules of antiviral treatment in 445 patients with chronic hepatitis C. Combination therapy (INF + Ribavirin) given for 6 mo. and monotherapy (INF) for 18 mo. were more effective than interferon alone given for 6 mo. Treatment with INF alone for 6 mo. was demonstrated to be insufficient.

[Cryptosporidiosis in HIV-positive patients]. / Kryptosporydioza u osób zakazonych HIV.

Cryptosporidium parvum is a coccidian parasite that affects millions of people worldwide. Clinical outcome of human cryptosporidiosis differs between immunocompetent and immnunodeficient individuals. C. parvum is responsible for causing protracted and life-threatening diarrhea, biliary, and pulmonary infections in immunocompromised persons, especially in patients with AIDS. Though no effective treatment has been found so far, early diagnosis may be useful in controlling the infection. Thirty-eight stool specimens obtained from 35 HIV-positive patients admitted to the Clinic of Infectious Diseases in Poznan, Poland, were examined for the detection of oocysts, coproantigen and DNA of Cryptosporidium using standard microscopic, immunologic and molecular diagnostic methods. The presence of Cryptosporidium was detected in 10 HIV-positive patients. Oocysts, coproantigen and DNA of this parasite were identified solely in one specimen while Cryptosporidium DNA was detected in 8 specimens. Cryptosporidium coproantigen was found only in one sample. Although, the PCR was the most useful technique in the detection of Cryptosporidium in HIV-positive patients it should be noted that PCR has many pitfalls and needs to be carefully controlled to avoid both false positive and false negative results.

Quantitative scanning thermal microscopy based on determination of thermal probe dynamic resistance.

Resistive thermal probes used in scanning thermal microscopy provide high spatial resolution of measurement accompanied with high sensitivity to temperature changes. At the same time their sensitivity to variations of thermal conductivity of a sample is relatively low. In typical dc operation mode the static resistance of the thermal probe is measured. It is shown both analytically and experimentally that the sensitivity of measurement can be improved by a factor of three by measuring the dynamic resistance of a dc biased probe superimposed with small ac current. The dynamic resistance can be treated as a complex value. Its amplitude represents the slope of the static voltage-current U-I characteristic for a given I while its phase describes the delay between the measured ac voltage and applied ac current component in the probe. The phase signal also reveals dependence on the sample thermal conductivity. Signal changes are relatively small but very repeatable. In contrast, the difference between dynamic and static resistance has higher sensitivity (the same maximum value as that of the 2nd and 3rd harmonics), and also much higher amplitude than higher harmonics. The proposed dc + ac excitation scheme combines the benefits of dc excitation (mechanical stability of probe-sample contact, average temperature control) with those of ac excitation (base-line stability, rejection of ambient temperature influence, high sensitivity, lock-in signal processing), when the experimental conditions prohibit large ac excitation.

Application of scanning thermal microscopy for investigation of thermal boundaries in multilayered photonic structures.

In current work the application of modified Scanning Thermal Microscopy (SThM) technique for thermal imaging of multilayered periodic photonic structures is presented. The measurements were carried out using non-standard operation mode of the SThM. The thermal probe was driven by the sum of DC and small AC currents. The main advantages of presented approach are mechanical stability of the probe during measurements and high sensitivity of AC signal detection by the use of lock-in amplifier. The amplitude and phase components of probe response signal are used for visualization and analysis of the thermal properties of the layer interfaces. Basing on topographic and thermal signals the thermal boundaries between layers were revealed and the periodicity of the structure was analyzed. Presented experiment indicates that the proposed method provides spatial resolution at least about 30% better than 100 nm, which is considered for standard nanofabricated thermal probes. Therefore, proposed technique may be successfully used for the thermal boundaries mapping, as well as for the high-resolution nanoscale imaging of thermal properties distribution. The results prove that thermal imaging provides additional information to that obtained by standard AFM imaging.