Fabrication of ZnO Nanorod-Based Hydrogen Gas Nanosensor

The nanofabrication of a hydrogen nanosensor from single ZnO branched nanorods using in-situ lift-out technique, performed in the chamber of a focused ion beam (FIB) system is disclosed. A self-assembled ZnO branched nanorod has been grown by a cost-effective and fast synthesis route using an aqueous solution deposition method and rapid thermal processing. The properties of the ZnO nanorod structures were analyzed by X-ray difhction, scanning electron microscopy, energy dispersion X-ray spectroscopy, transmission electron microscopy and micro-Raman spectroscopy. High quality ZnO nanorods were obtained with a 90% success rate for building nanodevices. The fabricated nanosensor can gauge 150 ppm hydrogen gas in the air at room temperature. The nanosensor has selectivity for other gases such as oxygen, methane, carbon monoxide and liquid propane gas. The single ZnO branched nanorod sensor also operates at low power of less than 5 microwatts

Assessment of the level of infringement of patients rights in dental care system

Rezumat. Cercetarea știinţifică iniţiată pe care această lucrare a ocazionat-o este determinată de constatarea unei situaţii relativ favorabile în asistenţa stomatologică din Republica Moldova în ceea ce privește respectarea drepturilor fundamentale ale omului, în general și ale pacientului în particular în asistenţa stomatologică. Studiul analizează serviciile medicale stomatologice în cadrul clinicilor stomatologice — ca parte componentă a sistemului de sănătate publică din Republica Moldova. În acest context, se pune în evidenţă, pe de o parte, semnificaţia pe care calitatea, echitatea și accesibilitatea serviciilor o au asupra stării de sănătate a pacientului, iar pe de altă parte, nivelul de profesionalism și respectare de către medicii stomatologi a drepturilor fundamentale ale omului, în particular ale pacientului. A fost aplicată metoda sociologică (Chestionarul, Focus-grup și Brain-storming) la medicii-specialiști și pacienţii din institiţiile stomatologice, pentru a stabili modul de respectare a drepturilor fundamentale ale omului, și în particular ale pacientului, în perioada ianuarie 2016-aprilie 2016.Summary. Scientific research that initiated this work gave rise to a findings which were determined by a relatively favorable situation in dental care of the The Republic of Moldova in respecting of fundamental human rights in general and particularly in the field of patient’s dental care. The study analyzes the in dental clinics — as a part of the public health system in the Republic of Moldova. In this context, on the one hand, meanings that the quality, equity and affordability have influence on the health of the patient, and on the other hand, the same the level of professionalism and respect by dentists of fundamental human rights. It was applied sociological method (questionnaires, focus-group and Brain-storming), specialists and patients in dental institutions to determine the observance of fundamental human rights, in particular the patient during January 2016-April 2016

Diagnosis and treatment evolution of the impacted canines

Rezumat. Introducere: Scopul acestei lucrări este de a determina poziţia cât mai precisă a dintelui inclus și a gradului său de mobilitate pentru alinierea lui pe arcada dentară cu un minim impact asupra dintelui tracţionat și a dinţilor adiacenţi. Materiale și metode: Acest studiu s-a bazat pe examinarea pacienţilor cu malocluzii, asociate cu incluzii dentare. A fost selectat un lot de 35 de pacienţi cu malocluzii, dintre care 22 de pacienţi cu incluzie de canin. Din acești pacienţi, 15 prezintă incluzia unui singur canin; 4 -prezintă incluzia a 2 canini și 2 — incluzii multiple asociate cu hipodonţie. Din numărul de pacienţi cu un singur canin inclus, 40 % prezintă incluzia dintelui 13, 47 % prezintă incluzia dintelui 23 și 13% prezintă incluzia dintelui 33. Toţi pacienţi au fost supuși unui examen clinic și paraclinic complex urmat de tratament, în perioada anilor 2013—2016. Pe parcursul intervenţiilor chirgicale s-au înregistrat indici importanţi de mobilitate a dintelui inclus cu ajutorul periotestului. Acești indici ne-au ajutat să alegem cea mai corectă metodă de tracţiune a dintelui pe arcada dentară și să stabilim forţa de tracţiune necesară care trebuie aplicată pentru a evita suprasolicitarea structurilor adiacente și a obţine rezultatul dorit. Rezultate: În baza protocolului de tratament și metodelor paraclinice de rX-imagistică a fost stabilită metoda de ancorare a dintelui fie prin implanuri ortodontice, a arcurilor NITI sau a arcurilor Kilroy și s-a obţinut deplasarea dintelui spre arcada dentară. Pentru deplasarea caninului inclus și alinierea dinţilor pe arcada dentară, pacienţilor li s-au aplicat aparatele ortodontice fixe. Putem afirma că in majoritatea cazurilor, dinţii incluși pot fi aliniaţi pe arcadă prin diagnosticarea timpurie a unghiului de înclinaţie a axului longitudinal și prin aplicarea tratamentului ortodontic-chirurgical, ceea ce ne permite restabilirea funcţiei și a echilibrului ocluzal. Concluzii: Cu ajutorul metodelor paraclinice și în special a periotestului, am reușit să obţinem informaţii despre gradul de mobilitate a dintelui și ce forţă trebuie să aplicăm asupra lui pentru a-l readuce în cavitatea bucală și a-l alinia pe arcada dentară. În urma acestui studiu, am demonstrat importanţa metodelor paraclinice de diagnostic a dintelui inclus punând accent pe metoda periotestul, ea fiind una suficient de obiectivă pentru tracţiunea caninului.Summary. Introduction: Research purpose is to determine the most accurate position of the impacted tooth for obtaining a good alignment of the teeth in the dental arcade with less impact on canines and adjacent teeth at the end of treatment. Material and methods: This study was based on the examination of the patients with malocclusions, associated with dental impaction. It was selected a group of 35 orthodontic patients, from which 22 were patients with canine impactions. From these 15 -had just one impacted canine; 4 had two impacted canines and just 2 had multiple impactions associated with hypodontia. From patients that had just one impacted canine 40 % had 13 tooth impacted; 47% had 23 tooth impacted and 13% had 33 tooth impacted. All patients passed a complex clinical and preclinical examination followed by treatment. During the surgical treatment, were registered important indexes of impacted tooth mobility with the help of periotest. These indexes have priority in choosing the most correct way for tooth’s traction on dental arch and for establishing the necessary force that must be applied, as not to damage the adjacent structures and to obtain the desired result. Discussion results: Based on treatment protocol and preclinical methods as X-rays we have selected the type of anchorage of the tooth either with the help of orthodontic implants, NITI arches or Kilroy arches for shifting the tooth to the dental arch. For moving, straightening and placing the tooth on dental arcade, patients have had to wear fixed orthodontic appliances. We can surely say that in majority of cases, impacted teeth can be aligned on arch by having an early diagnosis of the inclination angle of the longitudinal axis of the tooth and by having a mixed treatment both surgical and orthodontic. This options will establish a good functional situation and an ocluzal equilibrium. Conclusions: With the help of preclinical methods of examination and especially with the help of periotest, we managed to obtain sufficient information about the mobility degree of the tooth and to decide what type of force must we apply to the impacted tooth as to bring and align it in dental arcade. In this study I was trying to prove the importance of preclinical diagnosis of impacted tooth, making a significant accent on periotest method, this one being very objective for tooth traction

Enhanced UV and ethanol vapour sensing of a single 3-D ZnO tetrapod alloyed with Fe2O3 nanoparticles

Fabrication of multifunctional devices based on nano- and microstructures of a single semiconducting oxide is an important step for a better understanding of their maximum sensing properties and the base for the development of bottom-up nanotechnologies. In this work we have fabricated, for the first time devices based on a single or two interconnected ZnO tetrapods (T), doped with Fe and alloyed with Fe2O3 nanoparticles (NPs) and microparticles (MPs) in order to improve their sensing properties towards ultraviolet (UV) sensing and ethanol vapour (EtOH). Compared to pristine ZnO-T improved UV and gas sensing properties of Fe-doped ZnO-T were observed. By Fe2O3-alloying of Fe-doped ZnO-T further improvement in sensing properties was obtained with a reduced influence of the relative humidity (RH) on the sensing response. A gas sensing mechanism was proposed and discussed in detail based on the alloyed Fe2O3 NPs and MPs. The results presented here demonstrate the efficiency of doping and alloying of single ZnO microstructures with other semiconducting oxides to improve their sensing properties, including the decrease in influence of RH on the gas response and the rapidity of the sensors

Incidenţa apariţiei edentaţiilor parţiale şi clasificarea lor la copii şi adolescenţi

În acest articol a fost descrisă apariţia edentaţiilor la copii şi adolescenţi – pacienţi de diferite vârste. Folosind criteriile de apariţie, au fost clasifi cate edentaţiile parţiale în dentaţiile decidue şi mixte. Sunt descrise principiile de tartament protetic şi obiectivul ocluziei funcţionale la aceste vârste

Properties of ceria films grown on stainless steel by electrodeposition method

The study focuses on the elaboration of thin nanostructured ceria films, grown on the stainless steel, in view of high temperature fuel cell applications. Films were prepared electrochemically, via cathodic electrolytic deposition method, at low temperature (30 0C). Structural, morphological and composition analysis of the asgrown and annealed films were performed by means of XRD, Raman, SEM and EDX measurements

Orthodontic treatment for adults

Rezumat. Tot mai des la medicul ortodont se adresează pacienţi adulţi. Tratamentul ortodontic la adulţi face parte dintr-un tratament stomatologic complex. Necătînd la faptul că rezultatul se poate lăsa aşteptat, comparativ cu copiii, totuşi se pot obţine rezultate performante.Summary. The number of adult patient who need orthodontic treatment is growing. Orthodontic treatment for adults is a part of comprehensive dental treatment. Despite the fact that the result is more boringly, compared with children, performant results can be achieved

Tuning the Selectivity of Metal Oxide Gas Sensors with Vapor Phase Deposited Ultrathin Polymer Thin Films

Metal oxide gas sensors are of great interest for applications ranging from lambda sensors to early hazard detection in explosive media and leakage detection due to their superior properties with regard to sensitivity and lifetime, as well as their low cost and portability. However, the influence of ambient gases on the gas response, energy consumption and selectivity still needs to be improved and they are thus the subject of intensive research. In this work, a simple approach is presented to modify and increase the selectivity of gas sensing structures with an ultrathin polymer thin film. The different gas sensing surfaces, CuO, Al2O3/CuO and TiO2 are coated with a conformal 200 °C. The present study demonstrates possibilities for improving the properties of metal oxide gas sensors, which is very important in applications in fields such as medicine, security and food safety

Improved Long‐Term Stability and Reduced Humidity Effect in Gas Sensing: SiO 2 Ultra‐Thin Layered ZnO Columnar Films

The undoped and metal-doped zinc oxide columnar films (ZnO:Sn, ZnO:Fe, ZnO:Ag, and ZnO:Cu) are covered with an ultra-thin layer of SiO2 (10–20 nm). The electrical, UV, and volatile organic compounds (VOCs) sensing properties are evaluated under different ambient conditions for ≈7 months to investigate the impact of the top SiO2-layer on the long-term stability of samples. The obtained results show a high immunity of sensing properties of SiO2-coated samples to humidity. Furthermore, gas sensing measurements show that the loss in response after 203 days is significantly lower for coated samples indicating higher stability of sensing performance. For ZnO:Fe the gas response is reduced by about 90% after 203 days, but for SiO2-coated ZnO:Fe columnar films the gas response is slightly reduced by only 38%. The density functional theory (DFT) calculations show that water species bind strongly with the surface SiO2 layer atoms with a −0.129 e− charge transfer, which is, much higher compared to the interaction with ethanol and acetone. Calculations show strong binding of water species on the SiO2 layer indicating preferential absorption of water molecules on SiO2. The obtained results demonstrate an important role of the top SiO2 ultra-thin layer in order to produce humidity-tolerant sensitive devices

Additive Manufacturing as a Means of Gas Sensor Development for Battery Health Monitoring

Lithium-ion batteries (LIBs) still need continuous safety monitoring based on their intrinsic properties, as well as due to the increase in their sizes and device requirements. The main causes of fires and explosions in LIBs are heat leakage and the presence of highly inflammable components. Therefore, it is necessary to improve the safety of the batteries by preventing the generation of these gases and/or their early detection with sensors. The improvement of such safety sensors requires new approaches in their manufacturing. There is a growing role for research of nanostructured sensor’s durability in the field of ionizing radiation that also can induce structural changes in the LIB’s component materials, thus contributing to the elucidation of fundamental physicochemical processes; catalytic reactions or inhibitions of the chemical reactions on which the work of the sensors is based. A current method widely used in various fields, Direct Ink Writing (DIW), has been used to manufacture heterostructures of Al2O3/CuO and CuO:Fe2O3, followed by an additional ALD and thermal annealing step. The detection properties of these 3D-DIW printed heterostructures showed responses to 1,3-dioxolan (DOL), 1,2-dimethoxyethane (DME) vapors, as well as to typically used LIB electrolytes containing LiTFSI and LiNO3 salts in a mixture of DOL:DME, as well also to LiPF6 salts in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) at operating temperatures of 200 °C–350 °C with relatively high responses. The combination of the possibility to detect electrolyte vapors used in LIBs and size control by the 3D-DIW printing method makes these heterostructures extremely attractive in controlling the safety of batteries