Microgravity studies of solidification patterns in model transparent alloys onboard the International Space Station.

We review recent in situ solidification experiments using nonfaceted model transparent alloys in science-in-microgravity facilities onboard the International Space Station (ISS), namely the Transparent Alloys (TA) apparatus and the Directional Solidification Insert of the DEvice for the study of Critical Liquids and Crystallization (DECLIC-DSI). These directional-solidification devices use innovative optical videomicroscopy imaging techniques to observe the spatiotemporal dynamics of solidification patterns in real time in large samples. In contrast to laboratory conditions on ground, microgravity guarantees the absence or a reduction of convective motion in the liquid, thus ensuring a purely diffusion-controlled growth of the crystalline solid(s). This makes it possible to perform a direct theoretical analysis of the formation process of solidification microstructures with comparisons to quantitative numerical simulations. Important questions that concern multiphase growth patterns in eutectic and peritectic alloys on the one hand and single-phased, cellular and dendritic structures on the other hand have been addressed, and unprecedented results have been obtained. Complex self-organizing phenomena during steady-state and transient coupled growth in eutectics and peritectics, interfacial-anisotropy effects in cellular arrays, and promising insights into the columnar-to-equiaxed transition are highlighted.

In-situ X-ray monitoring of solidification and related processes of metal alloys.

X-ray radioscopy enables the in-situ monitoring of metal alloy processes and then gives access to crucial information on the dynamics of the underlying phenomena. In the last decade, the utilisation of this powerful imaging technique has been adapted to microgravity platforms such as sounding rockets and parabolic flights. The combination of microgravity experimentation with X-ray radioscopy has resulted in a leap in the understanding of fundamental science and has opened new paths in the fields of materials science. The present review focuses on the short history of this research, which includes facility developments, microgravity experiments and results obtained by partners of the XRMON (In-situ X-Ray MONitoring of advanced metallurgical processes under microgravity and terrestrial conditions) research project in the framework of the MAP (Microgravity Application Promotion) programme of the European Space Agency. Three illustrative research topics that were advanced significantly through the use of X-ray radioscopy will be detailed: solidification of metal alloys, metallic foam formation and diffusion in melts.

Measurement of non-isothermal transport coefficients in a near-eutectic succinonitrile/(d)camphor mixture.

We have determined nonisothermal diffusive transport coefficients of a succinonitrile-(d)camphor mixture with a composition of c = 0.239 wt.-frac. (d)camphor at a temperature of 318.2 K, which is close to the eutectic point. The employed experimental techniques are optical beam deflection in a Soret cell and photon correlation spectroscopy. The diffusion coefficient is D = (1.43 ± 0.04) × 10-10 m2 s-1, the thermodiffusion coefficient is DT = (2.00 ± 0.06) × 10-12 m2 s-1 K-1, and the Soret coefficient is ST = (1.40 ± 0.02) × 10-2 K-1. Camphor migrates toward the lower and succinonitrile migrates toward the higher temperatures. While the diffusion coefficient is in good agreement with the literature, the Soret coefficient has been determined for the first time. Our analysis shows that a significant concentration shift can be established in the liquid mixture in the presence of a temperature gradient. The mixture has a negative separation ratio, which leads to convective instabilities if heated from above.

Efficacy of a single session protocol for endodontic treatment in primary teeth: in vivo study.

AIMS: To determine the efficacy of a single session protocol (SSP) in the reduction of septic content of primary teeth root canals and identify the persistence of bacterial species associated with unsuccessful treatment. METHODS: Primary teeth root canals (16) with pulp necrosis and peri-radicular lesions were treated. Samples were collected at baseline (T1), and after chemo-mechanical preparation, before filling (T2). Identification of the microorganisms was determined using checkerboard DNA-DNA hybridisation. STATISTICAL ANALYSIS: Wilcoxon test was applied for comparison of mean number of species, proportion and mean count of each species between the evaluation times. RESULTS: Significant reductions were found in the mean number of bacteria species between T1 and T2 (p < 0.05), but not for the reduction in proportion (p > 0.05). There was a reduction (6.0-4.6) of the mean number of species associated with failure, without statistical significance. CONCLUSION: The SSP was capable of significantly reducing the septic content, even though, many of the bacteria associated with failure persisted at the time of root canal filling.

Posaconazole liquid vs tablet formulation in lung transplant recipients.

Posaconazole is an extended-spectrum triazole antifungal used in the treatment and prophylaxis of Aspergillus infections. It is available as oral suspension (POS-Liq) and delayed-release tablets (POS-Tab). The aim of this longitudinal, retrospective study was to compare the clinical effectiveness, toxicity and pharmacokinetics of POS-Liq vs POS-Tab in lung transplant recipients (LTx-recipients), who were treated with both formulations subsequently. Twenty-four consecutive LTx-recipients with 191 documented posaconazole trough levels (PTLs) for POS-Liq or POS-Tab were included. The administered daily doses were 300 mg for POS-Tab and 600 mg (prophylaxis) or 800 mg (therapy) for POS-Liq. Target PTLs were ≥700 ng/mL (prophylaxis) and ≥1250 ng/mL (therapy). The overall prophylactic and therapeutic response rates were 78% and 67%, respectively. No cases of hepatotoxicity or QT-prolongation were observed with either formulation. The achieved target PTLs were tripled under POS-Tab compared to POS-Liq with fewer risk factors for sub-therapeutic PTLs. Concomitant administration of POS-Tab significantly reduced the tacrolimus concentration-to-dose ratio (P = .001). We suggest the use of POS-Tab is appropriate for prophylaxis and therapy of Aspergillus infections in LTx-recipients, since POS-Tab displayed more reliable PTLs with no added adverse events. However, we recommend regular drug monitoring for POS-Liq and for therapy with POS-Tab and that immunosuppressant levels are monitored closely when the posaconazole formulation is switched.

Tooth fragment reattachment: a case report.

The aim of this article is to present a case report for the multidisciplinary treatment of anterior tooth fractures with invasion of the biologic width and pulpectomy. Successful esthetic and functional results were achieved by bonding the crown fragment, without any form of preparation or the utilization of intracanal posts.

[French translation, validation and adaptation of the Stigma Scale]. / Mesurer la stigmatisation perçue chez les personnes souffrant de troubles psychiques: traduction française, validation et adaptation de la Stigma Scale.

AIM: People suffering from mental illness are exposed to stigma. However, only few tools are available to assess stigmatization as perceived from the patient's perspective. The aim of this study is to adapt and validate a French version of the Stigma Scale (King et al., 2007 [8]). This self-report questionnaire has a three-factor structure: discrimination, disclosure and positive aspects of mental illness. Discrimination subscale refers to perceived negative reactions of others. Disclosure subscale refers mainly to managing disclosure to avoid discrimination and finally positive aspects subscale taps into how patients are becoming more accepting, more understanding toward their illness. METHOD: In the first step, internal consistency, convergent validity and test-retest reliability of the French adaptation of the 28-item scale were assessed in a sample of 183 patients. Results of confirmatory factor analyses (CFA) did not confirm the hypothesized structure. In the light of the failed attempts to validate the original version, an alternative 9-item short-form version of the Stigma Scale, maintaining the integrity of the original model, was developed based on results of exploratory factor analyses in the first sample and cross-validated in a new sample of 234 patients. RESULTS: Results of CFA did not confirm that the data fitted well to the three-factor model of the 28-item Stigma Scale (χ(2)/df=2.02, GFI=0.77, AGFI=0.73, RMSEA=0.07, CFI=0.77 and NNFI=0.75). Cronbach's α was excellent for discrimination (0.84) and disclosure (0.83) subscales but poor for potential positive aspects (0.46). External validity was satisfactory. Overall Stigma Scale total score was negatively correlated with the score on Rosenberg's Self-Esteem Scale (r=-0.49), and each subscale was significantly correlated with a visual analogue scale that referred to the specific aspect of stigma (0.43≤|r|≤0.60). Intraclass correlation coefficients between 0.68 and 0.89 indicated good test-retest reliability. The results of the CFA demonstrated that the items chosen for the short version of the Stigma Scale have the expected fit properties (χ(2)/df=1.02, GFI=0.98, AGFI=0.98, RMSEA=0.01, CFI=1.0 and NNFI=1.0). Considering the small number (three) of items in each subscale of the short version of the Stigma Scale, α coefficients for discrimination (0.57), disclosure (0.80) and potential positive aspects subscales (0.62) are considered as good. CONCLUSION: Our results suggest that the 9-item French short version of the Stigma Scale is a useful, reliable and valid self-report questionnaire to assess perceived stigmatization in people suffering from mental illness. The time of completion is really short and questions are well understood and accepted by the patients.

Cellular therapies for the treatment of non-union: the past, present and future.

Non-union fracture is a pathological condition having some impairment of the cellular part of the repair: a reduction of MSC and of the osteoblastic activation. Non union is therefore a good indication for cell-based therapies using stem cells. We described the rational of this treatment and described the technique of autologous bone marrow concentrate implantation that was until now used. With the development of stem cell research and regenerative medicine, we believed that therapy based on cytotherapy has great potential. In this review, clinical applications of cytotherapy are summarized and analyzed. Current problems and future challenges are discussed.

[The Ludwigshafen Osteoporosis Screening Questionnaire (LOS Questionnaire): result of the evaluation of anamnestic risk factors in osteoporosis diagnostics]. / Ludwigshafener Osteoporosescreeningbogen (LOS-Bogen) : Resultat aus der Evaluation anamnestischer Risikofaktoren in der Osteoporosediagnostik.

BACKGROUND: Osteoporosis is a major health problem worldwide and is included in the WHO list of the top ten major diseases. However, it is often undiagnosed until the first fracture occurs, due to inadequate patient education and lack of insurance coverage for screening tests. METHODS AND MATERIAL: In our study of 78 patients with metaphyseal long bone fractures, we searched for a correlation between anamnestic risk factors, bone-specific laboratory values, and the bone morphogenic density (BMD). Each indicator was examined as a possible diagnostic instrument for osteoporosis. The secondary aim of this study was to demonstrate the high prevalence of osteoporosis in patients with metaphyseal fractures. RESULTS: Of our fracture patients 76.9% had decreased bone density and 43.6% showed manifest osteoporosis in DXA (densitometry) measurements. Our modified LOS Questionnaire, identifying anamnestic risk factors, correlated highly significantly (p=0.01) with reduced BMD, whereas seven bone-specific laboratory values (p=0.046) correlated significantly. CONCLUSION: Anamnestic risk factors correlate with pathological BMD more than bone-specific laboratory values. The LOS Questionnaire used in this study would therefore function as a cost-effective primary diagnostic instrument for identification of osteoporosis patients.

[Results of nonunion treatment with bone morphogenetic protein 7 (BMP-7)]. / Ergebnisse der Pseudarthrosenbehandlung mit "bone morphogenetic protein 7" (BMP-7).

BACKGROUND: Complex patterns of impaired bone healing can result in a severe economic and social burden for the patient. Herein we describe the local application of recombinant human bone morphogenetic protein 7 (BMP-7). The goal of this prospective study is to review the indications, application and validation of this therapy. MATERIAL AND METHOD: From June 2002 to June 2008, we applied 101 BMP-7 treatments in 101 nonunions of 98 patients. The average age of the patients was 50 years (18-88 years). The gender composition was 29 women (30%) and 69 men (70%). Before BMP-7 application, patients had already underwent surgical treatement an average of 3.3 times (median 3, 1- to 13-times). We used BMP-7 "off-label" in all long bones. RESULTS: In 93 cases (92%), we observed proper bone healing. The average healing time was 4.8 months (range 1.5-11 months). The average time from injury to BMP-7 application was 18.4 months (3-84 months). In 65 cases, BMP-7 application was combined with re-osteosynthesis and autologous bone grafting. Serious side effects were not observed. CONCLUSIONS: BMP-7 should not be used as general treatment of nonunion in all patients, but appears to be effective for the treatment of complex cases. In clinical practice, the decision to proceed with off-label use of BMP-7 should be made on a case-by-case basis.

Differential gene expression analysis in fracture callus of patients with regular and failed bone healing.

OBJECTIVE: Although several systemic and local factors are known to impair fracture healing, there is still no explanation, why some patients with sufficient fracture stability, showing none of the existing risk factors, still fail to heal normally. An investigation of local gene expression patterns in the fracture gap of patients with non-unions could decisively contribute to a better understanding of the pathophysiology of impaired fracture healing. For the first time, this study compares the expression of a large variety of osteogenic and chondrogenic genes in patients with regular and failed fracture healing. METHODS: Between March 2006 and May 2007, a total of 130 patients who were surgically treated at the Berufsgenossenschaftliche Unfallklink Ludwigshafen were screened for the study. Tissue samples of patients with normal and failed fracture healing were collected intraoperatively. Patients were divided into groups depending on the fracture date, and only patients with fractures two to four weeks old and patients with non-unions more than 9 months old were included in the final analysis. For the gene expression analysis, a customised cDNA array - containing 226 genes involved in osteo- and chondrogenesis - was used. RESULTS: In the cDNA array analysis, the expression of eight genes was significantly elevated two-fold or more in the group with failed fracture healing relative to the normal controls. Conversely, no genes were found to be expressed at a higher level in the control group. The identified genes are supposed to be involved in extracellular matrix assembly, cytoskeletal structure, and differentiative and proliferative processes. CONCLUSIONS: The differences in gene expression pattern indicate a change in the composition and structure of the extracellular matrix, and a possible turn in the healing programme towards fibrous scar tissue formation, leading to non-union.

Compact x-ray microradiograph for in situ imaging of solidification processes: bringing in situ x-ray micro-imaging from the synchrotron to the laboratory.

A laboratory based high resolution x-ray radiograph was developed for the investigation of solidification dynamics in alloys. It is based on a low-power microfocus x-ray tube and is potentially appropriate for x-ray diagnostics in space. The x-ray microscope offers a high spatial resolution down to approximately 5 µm. Dynamic processes can be resolved with a frequency of up to 6 Hz. In reference experiments, the setup was optimized to yield a high contrast for AlCu-alloys. With samples of about 150 µm thickness, high quality image sequences of the solidification process were obtained with high resolution in time and space.

TRACP 5b and CTX as osteological markers of delayed fracture healing.

Radiological studies are the standard method to monitor fracture healing but they do not allow a timely assessment of bone healing. Biochemical markers react rapidly to changes in bone metabolism during fracture healing and could be an additional tool to monitor this process. The goal of this study was to observe changes in serum biomarkers and evaluate the possible differences in the serum levels of tartrate-resistant acid phosphatase 5b (TRACP 5b), total N-terminal propeptide of type I collagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal cross-linking telopeptide of type I collagen (CTX) in patients with normal and delayed fracture healing. Several serum samples were collected for one year after the surgical treatment of long bone fractures in 248 patients. From this large pool, 15 patients with atrophic nonunion were matched to 15 patients with normal bone healing. Post-operative changes in osteological markers were monitored during the 1st, 2nd, 4th, 8th, 12th and 52nd weeks. The patients were followed both clinically and radiologically for the entire one-year duration of the study. In the first week, the absolute values of CTX decreased significantly (p=0.0164) in cases of delayed fracture healing. The relative values of TRACP 5b were significantly decreased at weeks 4 (p=0.0066) and 8 (p=0.0043). BAP and PINP levels decreased in the first week followed by an increase, but there were no significant differences in the absolute or relative values during the healing process in both patient groups. For the first time, we have demonstrated changes in serum concentrations of TRACP 5b, PINP, BAP, and CTX during normal and delayed fracture healing. Characteristic changes in systemic TRACP 5b and CTX levels could reflect the initial process of successful fracture healing and may be used in clinical practice to monitor the healing process. Furthermore, it could be very important for determining the beneficial effects of additional treatments such as ultrasound or BMPs in clinical trials.

Usefulness of exhaled nitric oxide to guide risk stratification for bronchiolitis obliterans syndrome after lung transplantation.

The aim of this study was to assess fractional exhaled nitric oxide (FeNO) for the early diagnosis of bronchiolitis obliterans syndrome (BOS) after lung transplantation (LTX). 611 FeNO measurements in 166 consecutive patients were classified depending on BOS stage at the time of assessment and course during minimum follow-up of 3 months: (1) stable non-BOS, (2) unstable non-BOS, (3) stable BOS and (4) unstable BOS. Unstable course was defined as new onset of BOS≥1 or progression of BOS. FeNO before unstable course was significantly increased in comparison to their stable counterparts (non-BOS: 28.9 ± 1.2 ppb, n = 40 vs. 16.4 ± 0.8 ppb, n = 131 and BOS: 32.5 ± 1.3 ppb, n = 35 vs. 15.3 ± 0.8 ppb, n = 26; p = 0.01 each). Average time from FeNO reading to onset of deterioration was 117 ± 9 days in non-BOS and 136 ± 9 days in BOS patients. The positive and negative predictive value of FeNO >20 ppb for BOS was 69.0% and 96.9%, respectively. Serial measurements demonstrated significantly lower mean individual variation in stable recipients as compared to stable patients switching to unstable course (3.2 ± 0.3 ppb vs. 12.7 ± 1.4 ppb, p = 0.02). In particular, the excellent negative predictive value of persistently low FeNO readings for future BOS make FeNO assessments a useful tool for continuous risk stratification after LTX.

Effects of environmental parameters and irrigation on the turgor pressure of banana plants measured using the non-invasive, online monitoring leaf patch clamp pressure probe.

Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so-called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure P(p) that is highly correlated with the turgor pressure. Real-time recording of P(p) values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic-based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the P(p) values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non-invasive turgor pressure sensor system for elucidating the dynamics of short- and long-distance water transport in higher plants.

Cigarette smoking decreases TGF-b1 serum concentrations after long bone fracture.

TGF-b1 serum concentrations are considered to be one of the most promising markers of fracture healing. Previously, we demonstrated significant differences in the post-traumatic time courses of patients with timely and delayed fracture healing. The aim of this study was to evaluate possible differences in the serum concentrations of TGF-b1 in cigarette-smoking vs. non-smoking patients with timely and delayed fracture healing in order to understand pathophysiological pathways through which smoking impairs fracture healing.Serum samples were collected from 248 patients undergoing surgical treatment for long bone fractures within 1 year of surgery. Samples from 14 patients with atrophic-type delayed fracture healing were compared with 14 matched patients with normal bone healing. Each group included seven smokers and seven non-smokers. Post-operative serum concentrations were analysed at 1, 2, 4, 8, and 12 weeks as well as 1 year after surgery. The patients were monitored both clinically and radiologically for the entire duration of the study.All patients increased TGF-b1 serum concentrations after surgery. In patients with normal fracture healing, significantly higher TGF-b1 levels were observed in non-smokers (70 ng/ml) than in smokers(50 ng/ml) at the 4th week after surgery (p = 0.007). Also at the 4th week, in patients with delayed healing, significantly lower TGF-b1 levels were observed in smokers than in non-smokers (38 ng/ml vs.47 ng/ml, p = 0.021). However, no significant differences between non-smokers with delayed healing and smokers with normal healing (p = 0.151) were observed at the 4th week after surgery. TGF-b1 serum concentrations reached a plateau in all groups from the 6th to the 12th week after surgery, with a slight decrease observed in the final measurement taken 1 year after surgery.This study demonstrates that, after fracture, TGF-b1 serum concentrations are reduced by smoking,and this reduction is statistically significant during the 4th week after surgery. Our findings may help reveal the mechanism by which smoking impairs fracture healing. Furthermore, these results may help to establish a serological marker that predicts impaired fracture healing soon after the injury. Surgeons will not only be able to monitor the bone healing, but they will also be able to monitor the success of additional treatments such as ultrasound and bone morphologic proteins (BMPs).

[New insights in the differential diagnosis of bladder pain syndrome]. / Neue Erkenntnisse zur Differenzialdiagnostik des Bladder-Pain-Syndroms.

The diagnosis of bladder pain syndrome/interstitial cystitis (BPS/IC) is challenging, since pathogenetic mechanisms and the definition of clinical relevant parameters are still under lively discussion. The criteria recently proposed by the European Society for the Study of Interstitial Cystitis (ESSIC) define a collective of patients based on the cardinal symptom of bladder pain which is heterogeneous, and therefore cannot receive standardised consistent therapy. Thus an extended diagnosis based on molecular markers seems to be indicated to render individual pharmacotherapy possible, and to contribute to elucidation of BPS/IC pathogenesis. For this purpose we feel the vital need for taking a bladder biopsy. The diagnosis of BPS/IC should rely on 3 "columns": (1) clinical diagnostics; (2) histopathology; (3) molecular diagnostics/protein expression. Since a significant contribution of the 3 functional units of the bladder to the pathophysiology is most evident, the examinations should ideally include urothelium, lamina propria, and detrusor musculature. Generation of receptor profiles of the detrusor muscle represents a first attempt to define a diagnostic tool for the individualisation of BPS/IC pharmacotherapy. Other factors, e.g., beta-hCG expression in the urothelium, need further evaluation. Extended BPS/IC diagnostics could be realistically integrated into routine patient care within a clinic/laboratory network.

[Presentation of the french adaptation of McHale's coparenting scale for families with young children.] / Présentation de l'adaptation française de << l'échelle de coparentage >> de McHale pour familles avec jeunes enfants.

The aim of this paper is to present McHale's coparenting scale,a self-administered questionnaire enabling assessment of the quality of coparenting, and first steps in structural and construct validation of the French version. A total of 41 French speaking Swiss families and 84 US families completed this questionnaire and the Dyadic Adjustment Scale, a measure of marital satisfaction. The results of the Swiss families correspond to those of US families: first, items distributed into four factors (family integrity, conflict, affection and disparagement) and second, a partial link was found between quality of coparenting and marital adjustment. This finding supports the construct validity of the questionnaire, reflecting the established link between these two family sub-systems. Given that coparenting quality has a major influence on children's socio-affective development, the questionnaire will find great use in assessing not just negative features of coparenting, such as conflicts and disparagement, but also positive components such as warmth and support. This will be an important asset for research as well as clinical purposes.

A non-invasive probe for online-monitoring of turgor pressure changes under field conditions.

An advanced non-invasive, field-suitable and inexpensive leaf patch clamp pressure probe for online-monitoring of the water relations of intact leaves is described. The probe measures the attenuated output patch clamp pressure, P(p), of a clamped leaf in response to an externally applied input pressure, P(clamp). P(clamp) is generated magnetically. P(p) is sensed by a pressure sensor integrated into the magnetic clamp. The magnitude of P(p) depends on the transfer function, T(f), of the leaf cells. T(f) consists of a turgor pressure-independent (related to the compression of the cuticle, cell walls and other structural elements) and a turgor pressure-dependent term. T(f) is dimensionless and assumes values between 0 and 1. Theory shows that T(f) is a power function of cell turgor pressure P(c). Concomitant P(p) and P(c) measurements on grapevines confirmed the relationship between T(f) and P(c). P(p) peaked if P(c) approached zero and assumed low values if P(c) reached maximum values. The novel probe was successfully tested on leaves of irrigated and non-irrigated grapevines under field conditions. Data show that slight changes in the microclimate and/or water supply (by irrigation or rain) are reflected very sensitively in P(p).

Zinc oxide nanorod based photonic devices: recent progress in growth, light emitting diodes and lasers.

Zinc oxide (ZnO), with its excellent luminescent properties and the ease of growth of its nanostructures, holds promise for the development of photonic devices. The recent advances in growth of ZnO nanorods are discussed. Results from both low temperature and high temperature growth approaches are presented. The techniques which are presented include metal-organic chemical vapour deposition (MOCVD), vapour phase epitaxy (VPE), pulse laser deposition (PLD), vapour-liquid-solid (VLS), aqueous chemical growth (ACG) and finally the electrodeposition technique as an example of a selective growth approach. Results from structural as well as optical properties of a variety of ZnO nanorods are shown and analysed using different techniques, including high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), photoluminescence (PL) and cathodoluminescence (CL), for both room temperature and for low temperature performance. These results indicate that the grown ZnO nanorods possess reproducible and interesting optical properties. Results on obtaining p-type doping in ZnO micro- and nanorods are also demonstrated using PLD. Three independent indications were found for p-type conducting, phosphorus-doped ZnO nanorods: first, acceptor-related CL peaks, second, opposite transfer characteristics of back-gate field effect transistors using undoped and phosphorus doped wire channels, and finally, rectifying I-V characteristics of ZnO:P nanowire/ZnO:Ga p-n junctions. Then light emitting diodes (LEDs) based on n-ZnO nanorods combined with different technologies (hybrid technologies) are suggested and the recent electrical, as well as electro-optical, characteristics of these LEDs are shown and discussed. The hybrid LEDs reviewed and discussed here are mainly presented for two groups: those based on n-ZnO nanorods and p-type crystalline substrates, and those based on n-ZnO nanorods and p-type amorphous substrates. Promising electroluminescence characteristics aimed at the development of white LEDs are demonstrated. Although some of the presented LEDs show visible emission for applied biases in excess of 10 V, optimized structures are expected to provide the same emission at much lower voltage. Finally, lasing from ZnO nanorods is briefly reviewed. An example of a recent whispering gallery mode (WGM) lasing from ZnO is demonstrated as a way to enhance the stimulated emission from small size structures.