Growth and evolution of nickel germanide nanostructures on Ge(001).

Nickel germanide is deemed an excellent material system for low resistance contact formation for future Ge device modules integrated into mainstream, Si-based integrated circuit technologies. In this study, we present a multi-technique experimental study on the formation processes of nickel germanides on Ge(001). We demonstrate that room temperature deposition of ∼1 nm of Ni on Ge(001) is realized in the Volmer-Weber growth mode. Subsequent thermal annealing results first in the formation of a continuous NixGey wetting layer featuring well-defined terrace morphology. Upon increasing the annealing temperature to 300 °C, we observed the onset of a de-wetting process, characterized by the appearance of voids on the NixGey terraces. Annealing above 300 °C enhances this de-wetting process and the surface evolves gradually towards the formation of well-ordered, rectangular NixGey 3D nanostructures. Annealing up to 500 °C induces an Ostwald ripening phenomenon, with smaller nanoislands disappearing and larger ones increasing their size. Subsequent annealing to higher temperatures drives the Ni-germanide diffusion into the bulk and the consequent formation of highly ordered, {111} faceted Ni-Ge nanocrystals featuring an epitaxial relationship with the substrate Ni-Ge (101); (010) || Ge(001); (110).

Ba termination of Ge(001) studied with STM.

We use controlled annealing to tune the interfacial properties of a sub-monolayer and monolayer coverages of Ba atoms deposited on Ge(001), enabling the generation of either of two fundamentally distinct interfacial phases, as revealed by scanning tunneling microscopy. Firstly we identify the two key structural phases associated with this adsorption system, namely on-top adsorption and surface alloy formation, by performing a deposition and annealing experiment at a coverage low enough (∼0.15 ML) that isolated Ba-related features can be individually resolved. Subsequently we investigate the monolayer coverage case, of interest for passivation schemes of future Ge based devices, for which we find that the thermal evaporation of Ba onto a Ge(001) surface at room temperature results in on-top adsorption. This separation (lack of intermixing) between Ba and Ge layers is retained through successive annealing steps to temperatures of 470, 570, 670 and 770 K although a gradual ordering of the Ba layer is observed at 570 K and above, accompanied by a decrease in Ba layer density. Annealing above 770 K produces the 2D surface alloy phase accompanied by strain relief through monolayer height trench formation. An annealing temperature of 1070 K sees a further change in surface morphology but retention of the 2D surface alloy characteristic. These results are discussed in view of their possible implications for future semiconductor integrated circuit technology.

A molecular switch based on the manipulation of 1,3-dichlorobenzene on Ge(001) between two adsorption sites by inelastic tunneling electrons.

Meta-dichlorobenzene is adsorbed on Ge(001) and investigated by low temperature scanning tunneling microscopy. The molecule is altered between two adsorption sites by inelastic electron tunneling manipulation. These adsorption sites differ largely in conductivity. The necessary energy for switching the molecule between the sites and its polarity dependence indicate that the manipulation is initiated by the electronic excitation of the molecule.

Self-organisation of inorganic elements on Si(001) mediated by pre-adsorbed organic molecules.

A combined theoretical and experimental study on the adsorption of an isolated benzonitrile molecule on the Si(001) surface, followed by the adsorption of Al (group III), Pb (carbon group) and Ag (transition metal) is presented. It is shown that two new adsorption sites with enhanced reactivity are formed on the surface in the vicinity of the pre-adsorbed molecule. This is evidenced by the increase of the calculated binding energy of the metallic ad-atoms adsorbed at these sites. Experimentally, this enhanced local reactivity of the modified surface is only partially retained when more metallic atoms are adsorbed on the modified surface at room temperature. This is evidenced by the formation of 1-dimensional atomic chains (Pb, Al) attached to one side of the pre-adsorbed molecule.

Morphological and molecular characterization of novel population of CXCR4+ SSEA-4+ Oct-4+ very small embryonic-like cells purified from human cord blood: preliminary report.

Recently, we purified from adult murine bone marrow (BM) a population of CXCR4(+), Oct-4(+) SSEA-1(+), Sca-1(+) lin(-) CD45(-) very small embryonic-like (VSEL) stem cells and hypothesized that similar cells could be also present in human cord blood (CB). Here, we report that by employing a novel two-step isolation procedure -- removal of erythrocytes by hypotonic lysis combined with multiparameter sorting -- we could isolate from CB a population of human cells that are similar to murine BM-derived VSELs, described previously by us. These CB-isolated VSELs (CB-VSEL) are very small (3-5 micro m) and highly enriched in a population of CXCR4(+)AC133(+)CD34(+)lin(-) CD45(-) CB mononuclear cells, possess large nuclei containing unorganized euchromatin and express nuclear embryonic transcription factors Oct-4 and Nanog and surface embryonic antigen SSEA-4. Further studies are needed to see if human CB-isolated VSELs similar to their murine BM-derived counterparts are endowed with pluripotent stem cell properties.

The activity of erythrocyte sodium-proton exchanger in women with pregnancy- induced hypertension.

BACKGROUND: Hypertension that develops after 20 gestational weeks and is defined as pregnancy-induced hypertension (PIH). The main cause of PIH is vasoconstriction and the thickening of vascular media, which decreases vascular capacity and increases peripheral resistance. One of the theories postulated to explain this phenomenon is that a transmembrane sodium transport disorder causes an increase in intracellular sodium concentration. In the latest literature, special attention is paid to the role of the increased intracellular sodium concentration in the pathogenesis of essential hypertension (EH). One of the best documented phenotypes for EH is the increased activity of the sodium-proton exchanger (NHE). The aim of this study was to assess if increased NHE activity could be the mechanism responsible for the development of PIH. SUBJECTS AND METHODS: The study included 30 women: 10 pregnant women with PIH after gestational week 30, 10 women with physiological pregnancy after 30 gestational weeks, and 10 healthy non-pregnant women. NHE activity was determined according to Orlov's method as amiloride-sensitive H(+) efflux from acid-loaded cells. RESULTS: The NHE activity in the group of women with PIH was significantly higher than that in women with physiological pregnancy: 10.09 +/- 1.65 vs. 6.81 +/- 2.3 mmol/L RBC/h (p < 0.049) and in the group of non-pregnant women: 10.09 +/- 1.65 vs. 7.56 +/- 1.66 mmol/L RBC/h (p < 0.029). Erythrocyte NHE activity did not differ in the group of women with physiological pregnancy and in the group of non-pregnant women. CONCLUSION: These results seem to suggest that erythrocyte NHE activity is elevated in PIH pregnancies.

A novel serum free system for cloning human megakaryocytic progenitors (CFU-Meg). The role of thrombopoietin and other cytokines on bone marrow and cord blood CFU-Meg growth under serum free conditions.

Human megakaryocytic progenitors (CFU-Megs) are usually cloned in plasma clot cultures. Since the medium employed to prepare plasma clot contains animal or human serum, there exists a potential risk that CFU-Megs growing in vitro could be exposed to the serum derived megakaryopoietic inhibitors. To address this issue, we aimed to establish a relatively simple "serum free" cloning model for these progenitors. Accordingly, we found that if human bone marrow or cord blood CD34+ cells are plated in the methylcellulose medium containing serum substitute, and are stimulated with recombinant thrombopoietin (TpO), they exclusively form CFU-Meg colonies. Subsequently these colonies can be easily scored with an inverted microscope based only on their morphological criteria. We found that the cloning efficiency of CFU-Megs was higher in our serum free cloning system than in the traditional plasma clot cultures. Since the model proposed in this paper is relatively simple, and moreover does not require time consuming immunostaining to identify CFU-Meg colonies, it should be widely recommended for studying in vitro human megakaryopoiesis. We also found, that under serum free conditions TpO is crucial for CFU-Meg formation. In absence of TpO, neither gp 130 activating cytokines (IL-6, IL-11, LIF, CNTF) nor the other hematopoietic growth factors or cytokines (KL, IL-3, GM-CSF, EpO) were able, when added alone, to stimulate the growth of human CFU-Meg colonies. Finally, we report also that cord blood CD34+ cells are enriched in megakaryocytic progenitors, and moreover, CFU-Megs from cord blood possess a higher proliferative capacity than CFU-Megs isolated from normal adult bone marrow.

An improved serum free system for cloning human "pure" erythroid colonies. The role of different growth factors and cytokines on BFU-E formation by the bone marrow and cord blood CD34+ cells.

We have developed an efficient serum free culture model for cloning human erythroid progenitors. Accordingly, human bone marrow or cord blood CD34+ cells if plated in our serum free medium and stimulated with a mixture of EpO + KL, grow erythroid colonies exclusively. Cells isolated from these cultures express glycophorin-A (GPA-A), are CD33-, IIb/IIIa-, and finally all become hemoglobinized. By employing this system we also found out that cord blood CD34+ mononuclear cells (MNC) contain more BFU-E than adult marrow CD34+ MNC, moreover, the erythroid colonies formed by cord blood progenitors are significantly larger then the ones formed by the marrow cells. We have also compared the influence of different cytokines and growth factors, which were reported in the literature to costimulate BFU-E growth on cloning efficiency of human BFU-E cultured in our serum free medium. We found that from 20 different growth factors and cytokines tested, EpO dependent bone marrow BFU-E growth is costimulated only by KL, and to lesser degree also by IL-3, GM-CSF, TpO and IL-9. In contrast to marrow cells we observed that cord blood BFU-E in addition to KL, IL-3, GM-CSF, TpO, LIF and IL-9 were also costimulated by NGF-beta, FGF-1, FGF-2 and STK-IL. We found simultaneously that TPO which possess only negligible costimulatory effect on erythroid colony formation by bone marrow CD34+ cells, significantly costimulated the formation of erythroid colonies grown by cord blood CD34+ cells. Therefore, the cord blood CD34+ cells are largely committed to erythroid differentiation, and, moreover, they respond to a wider spectrum of the growth factors than their bone marrow counterparts.

Proinflammatory cytokines and other indications of inflammation in cervico-vaginal secretions and preterm delivery.

OBJECTIVES: To compare the usefulness of evaluating cervico-vaginal concentrations of proinflammatory cytokines (interleukin [IL]-1alpha, IL-1beta, IL-6 and IL-8) and procalcitonin (PCT), as well as serum levels of C-reactive protein (CRP), leucocytosis and band form granulocytes in the prediction of preterm delivery (PTD). METHODS: A total of 65 pregnant women experiencing preterm labor (PTL) were enrolled in the study. Concentrations of the studied markers in women who delivered prematurely and in women who, after treatment, delivered at term were compared. Receiver operator characteristic (ROC) curve analysis was used for all study parameters. RESULTS: Cervico-vaginal IL-6 and procalcitonin as well as serum CRP concentrations were higher in women who delivered prematurely than in those who delivered near term. A cervico-vaginal IL-6 level greater than 660 pg/ml was the best predictive value of preterm delivery (sensitivity, 50%; specificity 90%; positive predictive value [PPV], 85%; NPV, 62%; likelihood ratio, 5.17). Moreover, the area under the ROC curve of 0.75 for cervico-vaginal IL-6 was greater than for other markers. CONCLUSION: Although cervico-vaginal concentrations of procalcitonin and serum concentration of CRP are higher in women who deliver prematurely, only cervico-vaginal concentration of IL-6 is a good predictor of preterm delivery.

[Breus' mole in case of pregnancy in 22 years old primipara--a case report]. / Zasniad krwisty breusa u 22 letniej ciezarnej--opis przypadku.

A case of massive subchorial thrombohaematoma during pregnancy in 22 years old primipara is presented. The idea was to prolonged pregnancy as possible to term of lung maturity. Became described manner of diagnosis, treatments and way of delivery in this rare case of pathology.

[Estimation of selected methods of separation of hematopoietic cells from human umbilical cord blood]. / Ocena wybranych metod izolowania komórek hematopoetycznych z ludzkiej krwi pepowinowej.

Umbilical cord blood can determine alternative to bone marrow source of hematopoietic cells for transplantations. The aim of this work was estimation and comparison both of effectivity of separation of mononuclear cells from umbilical cord blood by means of Ficoll-Histopaque, Gradisol L and ammonium chloride and potential toxicity of Hoechst 33342, Rhodamin 123 and Pyronin Y on CD34+ cells. We showed superiority of density gradient centrifugation method (Ficoll-Histopaque, Gradisol L) over hypoosmotic lysis of erythrocytes and granulocytes (ammonium chloride). We ascertained similar efficiency of Ficoll and Gradisol. We showed also significant toxic influence of metabolic dyes, especially Hoechst 33342 on early hematopoietic cells.

[Fetal doppler flow velocimetry measurements as indications for cesarean section]. / Dopplerowskie badania przeplywowe plodu we wskazaniach do ciecia cesarskiego.

An effort was made to analyze fetal umbilical and cerebral arteries Doppler flow velocimetry patterns in pregnancies terminated with cesarean section emphasizing risk to the fetus. The flow velocimetry measurements were carried out at least 7 days prior to deliveries. The incidence of abnormal values of flow indices (SD, RI i PI) and ratio (CPR) were compared in pregnant women who delivered by cesarean section due to: I--threatening fetal distress (n = 28)--elective cesarean sections were performed on pregnant women with chronic placental insufficiency symptoms; II--fetal distress (n = 22)--emergency cesarean sections; III--obstetric indications for cesarean section (no symptoms of fetal distress were present). Increased resistance in placental circulation, and decreased resistance in cerebral vessels finally leading to reversed diastolic umbilical flow occur more often in pregnant women with chronic placental insufficiency. Umbilical factor seems to be responsible for the observed in every studied group higher incidence of abnormal flows in middle cerebral than in umbilical artery. Fetal Doppler flow velocimetry of umbilical and middle cerebral arteries allow for finding of the most proper time of high-risk pregnancy termination, hence should be considered in the elective cesarean sections.

[Clinical analysis of preterm labor]. / Kliniczna analiza porodów przedwczesnych.

576 patients with preterm deliveries that occurred between the 22nd to 37th gestation weeks were undergone clinical analysis. The material was collected in the years 1995 to 1999 at Clinic of Obstetric and Perinatology of Pomeranian Academy of Medicine in Szczecin. In our study the rate of preterm delivery was 10.5%. Special attention was paid to mother's age, obstetrics history, socioeconomic, medical and psychogenic conditions of pregnant women, condition of infants, infant mortality and their birth-weight. The rate of premature preterm rupture of fetal membranes was 52.7%. The frequency of caesarean sections in our study in preterm births was about 50% like in other publications and the most important indication for them was amnionitis. In almost 40% the general state of infants was poor and medium. Almost 25% of preterm deliveries is connected with other systemic diseases during pregnancy.

[Umbilical cord blood cytokines: a new diagnostic parameter? A preliminary report]. / Cytokiny krwi pepowinowej--nowy parametr rokowniczy? Doniesienie wstepne.

The aim of neonatologist is to anticipate clinical status of newborn immediately after delivery. Important are all parameters helpful in determining perinatal outcome. Particular attention is paid to proinflammatory cytokines: IL-1 alpha, IL-1 beta, IL-6, IL-8 and TNF alpha. The aim was to verify a relationships between umbilical cord blood cytokines and way of delivery, umbilical factor and clinical status of newborn in perinatal period. Newborns with lower 10 min Apgar score had higher levels of umbilical blood cytokines. Elevated IL-6 and IL-8 levels were found in newborns with subsequently diagnosed bacterial infection. Higher levels of cytokines were found in umbilical blood of newborns who passed meconium into the amniotic sac and who required an incubator. Proinflammatory cytokines, especially IL-6 and IL-8 may indicate the newborn clinical status in perinatal period.

[A case report of rubella embryopathy in pregnancy complicated by placental insufficiency]. / Opis przypadku embriopatii rózyczkowej powiklanej przewlekla niewydolnoscia lozyska.

This is a case report of sever rubella empryopathy confirmed by IgM and IgG titers estimation in newborn blood. This pregnancy was complicated by prolonged placenta insufficiency (oligohyramnions and IUGR). The cesarian section was done in 35 weeks of pregnancy. The newborn died in 9 days after delivery. Cause of death was sepsis, vitium cordis congenitum and respiratory insufficiency.

[The effect of umbilical cord blood cytokines on clonogenicity of hemopoietic stem cells isolated from umbilical cord blood]. / Badania nad wplywem wybranych endogennych cytokin prozapalnych krwi pepowinowej na potencjal klonogenny macierzystych komórek krwiotworzenia izolowanych z krwi pepowinowej.

Human umbilical cord blood contains haematopoietic stem cells, which are a potential source of cells for hematopoietic transplants. Early cord blood hematopoietic cells are influenced by so called proinflammatory cytokines, which are present in cord blood serum. In this study we tried to correlate the concentration of these cytokines with the number, viability and clonogenicity of cord blood mononuclear cells. Accordingly, cord blood samples were harvested by employing an "open" collection method. Subsequently, we measured in those samples the concentration of selected pro inflammatory cytokines (Il-1 alpha, Il-1 beta, Il-6, Il-8 and TNF alpha), number of mononuclear cells and evaluated in vitro clonogenicity of myeloid progenitors (CFU-GM). We found the negative correlation between number of mononuclear cells and concentration of TNF alpha, and between number of detectable CFU-GM and concentration of IL-1 beta. Other cytokines, which were studied in this report did not correlate with evaluated parameters.

[Significance of doppler ultrasound examination in successful termination of pregnancy with arterial hypertension in the course of chronic proliferative glomerulonephritis]. / Znaczenie badania dopplerowskiego w pomyslnym zakonczeniu ciazy z ciezkim nadcisnieniem tetniczym w przebiegu glomerulonephritis proliferativa chronica.

Diagnostic and therapeutic management in pregnant woman with severe arterial hypertension in course of glomerulonephritis proliferativa chronica at kidney insufficiency stage was presented. Ultrasonic biometry, biophysical fetal profile and Doppler ultrasound velocimetry were performed for antenatal fetal surveillance. Relation between a degree of fetal compromise (abnormal qualitative Doppler velocimetry indices and pre-pathological or even pathological NST) and a long-drawn increase of both diastolic and systolic blood pressure was stated. Doppler ultrasound examination gave possibility of monitoring and evaluation of fetal distress and verification of its treatment efficacy, what would allow to prolong the pregnancy for 12 days and was a definite contribution to its successful outcome.

[Labor in women with heart and great vessel diseases]. / Poród u kobiet z chorobami serca i duzych naczyn.

The way of termination of pregnancy was retrospectively analysed in 95 pregnant women with heart and/or great vessels diseases, hospitalised in years 1989-1991 and 1995-1996 in the Department of Obstetrics and Perinatology of Pomeranian Medical Academy. The condition of cardiovascular system was assessed according to NYHA classification on admission and just before delivery with participation of an experienced cardiologist. Kind of heart disease, mode and period of delivery, perinatal cardiovascular symptoms, duration of delivery and duration of hospitalisation, weight and clinical condition of the newborns were taken under consideration. In more than half of cases (60%) cesarean sections were performed. Among the indications for elective cesarean section cardiological indications formed the dominant group (29.5%). During perinatal period deterioration of circulatory system sufficiency associated with increase of number of cesarean sections were observed.

[The management of cervical cancer cases in pregnancy and puerperium]. / Postepowanie w przypadkach raka szyjki macicy w czasie ciazy i pologu.

UNLABELLED: Cervical cancer in women during pregnancy and puerperium is a serious diagnostic and therapeutic problem. Twelve multiparas with confirmed cervical cancer during pregnancy, delivery and puerperium were examined. The mean age of the group was 35. In two of them cervical cancer was diagnosed in the second trimester, in 5 in the third trimester and in 5 in puerperium. Clinical stage according to FIGO was as follow: Ib--9 patients, IIa--2 patients, III--1 patient. In two patients operated in the second trimester--extended hysterectomy was performed. In four women cesarean section with extended hysterectomy and lymphadenectomy was performed. Only one patient in third trimester had cesarean section and in the same time unradical hysterectomy because of bleeding. In two patients in puerperium extended hysterectomy was performed (Meigs operation). Three patients underwent only radiotherapy. All patients who were operated on underwent subsequent radiotherapy. CONCLUSIONS: Cervical cancer during pregnancy and puerperium is diagnosed very late, usually in advanced stage. It is connected with lack of clinical and cytological examination of women before pregnancy. Principles of treatment of cervical cancer in pregnancy and puerperium do not differ from those applicable in other patients.