Accuracy of digital guided implant surgery: expert consensus on nonsurgical factors and their treatments / 口腔疾病防治

@#The standardized workflow of computer-aided static guided implant surgery includes preoperative examination, data acquisition, guide design, guide fabrication and surgery. Errors may occur at each step, leading to irreversible cumulative effects and thus impacting the accuracy of implant placement. However, clinicians tend to focus on factors causing errors in surgical operations, ignoring the possibility of irreversible errors in nonstandard guided surgery. Based on the clinical practice of domestic experts and research progress at home and abroad, this paper summarizes the sources of errors in guided implant surgery from the perspectives of preoperative inspection, data collection, guide designing and manufacturing and describes strategies to resolve errors so as to gain expert consensus. Consensus recommendation: 1. Preoperative considerations: the appropriate implant guide type should be selected according to the patient's oral condition before surgery, and a retaining screw-assisted support guide should be selected if necessary. 2. Data acquisition should be standardized as much as possible, including beam CT and extraoral scanning. CBCT performed with the patient’s head fixed and with a small field of view is recommended. For patients with metal prostheses inside the mouth, a registration marker guide should be used, and the ambient temperature and light of the external oral scanner should be reasonably controlled. 3. Optimization of computer-aided design: it is recommended to select a handle-guided planting system and a closed metal sleeve and to register images by overlapping markers. Properly designing the retaining screws, extending the support structure of the guide plate and increasing the length of the guide section are methods to feasibly reduce the incidence of surgical errors. 4. Improving computer-aided production: it is also crucial to set the best printing parameters according to different printing technologies and to choose the most appropriate postprocessing procedures.

Lipid nanovehicles overcome barriers to systemic RNA delivery: Lipid components, fabrication methods, and rational design

Lipid nanovehicles are currently the most advanced vehicles used for RNA delivery, as demonstrated by the approval of patisiran for amyloidosis therapy in 2018. To illuminate the unique superiority of lipid nanovehicles in RNA delivery, in this review, we first introduce various RNA therapeutics, describe systemic delivery barriers, and explain the lipid components and methods used for lipid nanovehicle preparation. Then, we emphasize crucial advances in lipid nanovehicle design for overcoming barriers to systemic RNA delivery. Finally, the current status and challenges of lipid nanovehicle-based RNA therapeutics in clinical applications are also discussed. Our objective is to provide a comprehensive overview showing how to utilize lipid nanovehicles to overcome multiple barriers to systemic RNA delivery, inspiring the development of more high-performance RNA lipid nanovesicles in the future.

Una Revisión de los tipos de Fraude Científico más Frecuentes / A Review of the most frequent types of Scientific Fraud

La presión que existe hoy por publicar ha llevado a que muchos investigadores cometan malas conductas científicas, siendo el fraude la más grave de todas. Este ocurre en forma de fabricación, falsificación, plagio, problemas de autoría, manipulación de imágenes y publicaciones redundantes. El fraude científico se define como una tergiversación deliberada por parte de alguien que conoce la verdad. En la historia de la humanidad se han conocido importantes casos de fraude científico, dentro de ellos se pueden destacar: el hombre de Piltdown, caso Shinichi Fujimura, el escándalo de las vacunas, caso Pearce, el caso Yoshitaka Fujii, entre otros. Con el objetivo de neutralizar el fraude, se han desarrollado diferentes estrategias dirigidas a detectarlo, dentro de ellas encontramos: evaluación mediante pares evaluadores, programas de Conducta de Investigación Responsable (RCR), regulaciones que la misma comunidad científica realiza, donde encontramos la fundación PubPeer y el blog For Better Science. Del mismo modo, se han impuesto diferentes medidas para contrarrestar el fraude, tales como: transparencia de las presiones y oportunidades, disponibilidad pública de los datos que sustentan la hipótesis y denuncia pública de los fraudes científicos. El impacto de un fraude trae consecuencias importantes para la ciencia, estudiar a partir de información falsa o errónea conlleva a un gran retroceso en los avances científicos del mundo actual. Es responsabilidad de cada uno ser consciente de lo que se escribe y lo que se lee, ya que como se sabe, esa es la única manera de combatirlo. Como investigadores somos responsables de actuar éticamente en nuestras investigaciones y tener conocimiento de las medidas que existen hoy para detectar y combatir el fraude científico.

The pressure to publish today has led many researchers to commit scientific misconduct, fraud being the most serious of all. This occurs in the form of fabrication, falsification, plagiarism, authorship problems, image manipulation, and redundant posting. Scientific fraud is defined as deliberate misrepresentation by someone who knows the truth. In the history of humanity, important cases of scientific fraud have been known, among them the following can be highlighted: the Piltdown man, the Shinichi Fujimura case, the vaccine scandal, the Pearce case, the Yoshitaka Fujii case, among others. In order to neutralize fraud, different strategies have been developed to detect it, among them we find: evaluation by peer reviewers, Responsible Research Conduct (RCR) programs, regulations that the scientific community itself carries out, where we find the PubPeer Foundation and the For Better Science blog. Similarly, different measures have been imposed to counteract fraud, such as: transparency of pressures and opportunities, public availability of the data that support the hypothesis, and public denunciation of scientific fraud. The impact of a fraud has important consequences for science, studying from false or wrong information leads to a great setback in scientific advances in the world today. It is the responsibility of each one to be aware of what is written and what is read, since as is known, that is the only way to combat it. As researchers we are responsible for acting ethically in our research and being aware of the measures that exist today to detect and combat scientific fraud.

Methods for the analysis of uranium aerosol concentration in the workplace of uranium processing and fuel fabrication facilities / 中国辐射卫生

Objective To establish a method for uranium aerosol sample collection, dry ashing treatment, and laboratory laser-fluorescence measurement in the workplace of uranium processing and fuel fabrication facilities. Methods Through optimization experiments, the effects of sampling flow, sample pH value, and test temperature on uranium aerosol concentration results were studied, and the detection limit, precision, and recovery rate of the method were tested. Results Under the optimal test conditions, the detection limit of the method was 0.025 ng/mL; the minimum detectable concentration of 1 m3 of aerosol samples was 1.25 × 10−3 μg/m3; the relative standard deviation (RSD) of the measurement results was less than 5%; the recovery rate was between 96% and 104%. Conclusion The detection limit, precision, and accuracy of the method meet the testing requirements for uranium aerosol samples in the workplace of uranium processing and fuel fabrication facilities.

Occupational Characteristics of Semiconductor Workers with Cancer and Rare Diseases Registered with a Workers' Compensation Program in Korea

BACKGROUND: The aim of this study was to describe the types of diseases that developed in semiconductor workers who have registered with the Korea Workers' Compensation and Welfare Service (KWCWS) and to identify potential common occupational characteristics by the type of claimed disease. METHODS: A total of 55 semiconductor workers with cancer or rare diseases who claimed to the KWCWS were compared based on their work characteristics and types of claimed diseases. Leukemia, non-Hodgkin lymphoma, and aplastic anemia were grouped into lymphohematopoietic (LHP) disorder. RESULTS: Leukemia (n = 14) and breast cancer (n = 10) were the most common complaints, followed by brain cancer (n = 6), aplastic anemia (n = 6), and non-Hodgkin lymphoma (n = 4). LHP disorders (n = 24) accounted for 43%. Sixty percent (n = 33) of registered workers (n = 55) were found to have been employed before 2000. Seventy-six percent (n = 42) of registered workers and 79% (n = 19) among the registered workers with LHP (n = 24) were found to be diagnosed at a relatively young age, ≤40 years. A total of 18 workers among the registered semiconductor workers were finally determined to deserve compensation for occupational disease by either the KWCWS (n = 10) or the administrative court (n = 8). Eleven fabrication workers who were compensated responded as having handled wafers smaller than eight inches in size. Eight among the 18 workers compensated (44 %) were found to have ever worked at etching operations. CONCLUSION: The distribution of cancer and rare diseases among registered semiconductor workers was closely related to the manufacturing era before 2005, ≤8 inches of wafer size handled, exposure to clean rooms of fabrication and chip assembly operations, and etching operations.

Titanium Powder Coating Using Metal 3D Printing: A Novel Coating Technology for Cobalt-Chromium Alloy Implants

BACKGROUND: Three-dimensional (3D) printing with a direct metal fabrication (DMF) technology has been innovatively introduced in the field of surface treatment of prostheses. The purpose of this study was to determine whether such modifications on the surface of cobalt-chromium (CoCr) alloy by titanium powder coating using DMF improves the osseointegration ability of CoCr alloy. METHODS: We compared the in vitro and in vivo ability of cells to adhere to DMF-coated CoCr alloy with machining. Biological and morphological responses to human osteoblast cell lines were examined by measuring cell proliferation rate and observing expression of actin filament. For in vivo study, we inserted different specimens in each medulla of the distal femurs of rabbit. After 3 months, the distal femurs were harvested, and a push-out test and histomorphometric analyses were performed. RESULTS: The cell proliferation rate and cell adhesion in the DMF group were higher compared with those in the machined group. Human osteoblast cells on the DMF-coated surface were more strongly adhered and well-proliferated compared with those on the other surface. In the in vivo test, there was a significant difference in the ultimate shear strength between the DMF and machined groups (2.49 MPa vs. 0.87 MPa, respectively, p = 0.001). In the histomorphometric analysis, there was a significant difference in the mean bone-to-implant contact percentages between the DMF and machined groups (72.3 ± 6.2% vs. 47.6 ± 6.9%, respectively, p < 0.001). CONCLUSION: Titanium coating of CoCr alloy with 3D metal printing provides optimal surface characteristics and a good biological surface both in vitro and in vivo.

Mechanically Reinforced Extracellular Matrix Scaffold for Application of Cartilage Tissue Engineering

Scaffolds with cartilage-like environment and suitable physical properties are critical for tissue-engineered cartilage repair. In this study, decellularized porcine cartilage-derived extracellular matrix (ECM) was utilized to fabricate ECM scaffolds. Mechanically reinforced ECM scaffolds were developed by combining salt-leaching and crosslinking for cartilage repair. The developed scaffolds were investigated with respect to their physicochemical properties and their cartilage tissue formation ability. The mechanically reinforced ECM scaffold showed similar mechanical strength to that of synthetic PLGA scaffold and expressed higher levels of cartilage-specific markers compared to those expressed by the ECM scaffold prepared by simple freeze-drying. These results demonstrated that the physical properties of ECM-derived scaffolds could be influenced by fabrication method, which provides suitable environments for the growth of chondrocytes. By extension, this study suggests a promising approach of natural biomaterials in cartilage tissue engineering.

Fabrication of Walking Function Orthosis for Patients with Leg Length Discrepancy / 中国康复理论与实践

Objective To study the design and fabricating method of orthosis for patients with leg length discrepancy. Methods Ischial weight bearing orthosis with prosthetic feet was made through efforts from weight,beauty and durabili-ty.The fabrication process included taking a negative plaster cast,modifying the positive model,forming,align-ment,and fitting the device to the patients. Results The orthosis was compensated for the patients'height with good appearance and convenience wearing. Conclusion Ischial weight bearing orthosis with prosthetic feet can help patients reconstruct walking function,therefore can be recommended.

Development of Piezoelectric Oscillation-Based Microarray Spotting System / 分析化学

A new type of piezoelectric oscillation-based non-contact spotting mode has been developed to overcome the disadvantages of traditional non-contact spotting modes including complicated operation procedure, cleaning difficulty of spotting needle, large sample consumption of electromagnetic microvalve and high spotting cost of piezoelectric inkjet based non-contact spotting mode. In the device, the capillary spotting needle and the piezoelectric driving device are two independent units used for replacing and cleaning capillary spotting needle. The glass capillary spotting needle is prepared by the laser melting method with adjustable diameter and low cost. The sample spotting volume of the device can be easily adjusted in the range of 10Symbolm_10-10Symbolm_9 by changing the amplitude and frequency of piezoelectric ceramic. A microarray spotting system is developed by the combination of the piezoelectric oscillation-based non-contact spotting mode and three dimensional precision displacement control technology. The multiple parameters of as-prepared microarray spotting system have been tested including spotting volume, density of spot and spotting precision. The experimental results indicate that the minimum volume of single spot with 320 pL and the highest density of spot with 4000 spots/cm2 can be achieved by the as-prepared microarray spotting system. Furthermore, the as-prepared microarray spotting system can also be employed to fabricate patterned interface.

The value of the combined detection of IMA, NT-proBNP and dynamic electrocardiogram in the diagnosis of silent myocardial ischemia / 中国医学装备

Objective:To evaluate the clinical value of combined detection of ischemia modified albumin(IMA), N-terminal pro brain natriuretic peptide(NT-proBNP) and dynamicelectrocardiogram(DEG) in the diagnosis of silent myocardial ischemia.Methods: IMA, NT-proBNP and DEG of 114 patients with silent myocardial ischemia who were suspected coronary heart disease were detected, and then these results were compared and analyzed with the results of coronary angiography(CAG).Results: In 114 patients with suspected coronary heart disease, 68 cases(59.65％)were positive as the results of CAG. And there were 60 cases were positive as the results of IMA detection, and the specificity and sensitivity of IMA compared with CAG were 82.61％ and 88.24％, respectively. There were 63 cases were positive as the results of NT-proBNP, and the specificity and sensitivity of NT-proBNP compared with CAG were 80.43％ and 92.64％, respectively. There were 57 cases were positive as the results of DEG, and the specificity and sensitivity of DEG compared with CAG were 86.96％ and 83.82％, respectively. While there were 66 cases were positive as the combined detection of the three methods, and specificity and sensitivity of the combined detection compared with CAG were 95.65％ and 97.06％, respectively. Therefore, the specificity and sensitivity of combined detection were significantly higher than that of alone detection of IMA, NT-proBNP and DEG (F=140.637,F=255.467,P<0.05).Conclusion: The comprehensive analysis for the combined detections of IMA, NT-proBNP and DEG can increase both of the specificity and sensitivity of diagnosis, and it can be used as a important screening method for earlier finding silent myocardial.

Fabrication of provisional restoration on freshly prepared tooth: indirect and direct technique.

Background: Provisional restorations are fabricated to protect the prepared tooth structure during period between the preparation and the final restoration, and the techniques applied are direct, indirect and indirect direct. Various materials are used to fabricate provisional restoration, such as, preformed crown, acrylic, metal shell, composite, etc. Objectives: The study was designed to evaluate the advantages of fabrication of provisional restorations by indirect technique over direct technique. Methods: This prospective comparative study carried out in the Department of Prosthodontics, Faculty of Dentistry, Bangabandhu Sheikh Mujib Medical University, Dhaka, from January 2006 to December 2007, included 20 patients each for insertion of provisional restorations fabricated by indirect (group A) and direct (group B) technique. Outcome was evaluated on the basis of marginal adaptation, biocompatibility and aesthetic status. Results: On day 7 of provisional restoration, grade I marginal adaptation were observed in 75% and 40% of group A and group B patients, respectively, and on day 15 were 75% and 20%, respectively. Grade I biocompatibility on day 7 of group A patients were 100% and group B 30%, and on day 15 was 95% and 35%, respectively. Grade I aesthetic status on day 7 were in 100% of both group A and group B patients, and on day 15 was 95% and 85%, respectively. None of the patients was in grade III, either in marginal adaptation, biocompatibility or aesthetic status. Conclusion: Indirect provisional restoration is better and safer in relation to marginal adaptation, biocompatibility and aesthetic status.

Use of temporary filling material for index fabrication in Class IV resin composite restoration

When a patient with a fractured anterior tooth visits the clinic, clinician has to restore the tooth esthetically and quickly. For esthetic resin restoration, clinician can use 'Natural Layering technique' and an index for palatal wall may be needed. In this case report, we introduce pre-restoration index technique on a Class IV defect, in which a temporary filling material is used for easy restoration. Chair-side index fabrication for Class IV restoration is convenient and makes a single-visit treatment possible.

Prosthodontic rehabilitation of hemimaxillectomy patient with hollow bulb obturator.

Abstracts: One of the most rapidly growing areas of dentistry from the standpoint of both interest and need is maxillofacial prosthetics. The research on cancer has made understanding and treatment of this dreadful disease a possibility, still the rehabilitation of these patients is a daunting job, and is more so in post-surgical cases. With the advent of new materials and techniques, vast improvement in rehabilitation of maxillofacial patients has been realized. The objective of this case report was to obturate acquired palatal defects and allowing the restoration of functions such as esthetics, mastication, deglutition and speech. This report throws light on the simplified technique to prepare hollow bulb obturator using shim fabrication. This technique results in a prosthesis which is light in weight and aids in better retention and patient’s comfort.

Zirconium for esthetic rehabilitation: An overview.

The demand for esthetic restorations has resulted in an increased use of dental ceramics for anterior and posterior restorations. A few decades ago, all-ceramic restorations were restricted to treatment in the anterior region, but now all-ceramic restorations can be made anywhere in the dentition. The properties of traditional ceramic materials, however, have limited their use to single crowns; larger restorations have been inadvisable because of insufficient strength. In attempts to meet the requirements for dental materials and improve strength and toughness, several new ceramic materials and techniques have been developed during the past few decades The paper reviews the current literature on dental zirconia with respect to survival, properties, marginal fit, cementation, esthetics and suggests clinical recommendations for their use.

Exposure to Volatile Organic Compounds and Possibility of Exposure to By-product Volatile Organic Compounds in Photolithography Processes in Semiconductor Manufacturing Factories

OBJECTIVES: The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. METHODS: A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. RESULTS: A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. CONCLUSION: Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.

Review on Potential Risk Factors in Wafer Fabrication Process of Semiconductor Industry / 대한산업의학회지

OBJECTIVES: To associate work in the semiconductor industry, including silicon wafer fabrication, with cancer risks or mortality and other adverse health effects, the operation of wafer fabrication should initially be understood. A detailed study on the fabrication operation allows retrospective exposure to be assessed and wafer fabrication workers to be classified into similar exposure groups. Therefore, the objective of this study was to comprehensively review silicon wafer fabrication operations and related hazardous materials and agents. METHODS: The literatures related to semiconductor industry processes were reviewed from an occupational health viewpoint based on wafer manufacturing, wafer fabrication and packaging. The focus was especially related to the hazardous materials used in wafer fabrication industries. RESULTS: During the fabrication of silicon wafers, many toxic chemicals, a strong electric field and hazardous equipment are used. The process allows the integration of a three-dimensional array of electric circuits onto a silicon wafer substrate. Wafers are sliced from single crystal silicon and subject to a series of steps during the fabrication process, which alternatively adds and then selectively removes materials in layers from the surface of the wafer to create different parts of the completed integrated circuit. There are four major steps in this process; patterning, junction formation, thin film and metallization. CONCLUSIONS: In order to associate exposure to the hazard agents generated during wafer fabrication operations with adverse health effects the details of the operation should be completely studied, which will be helpful in both exposure assessments and epidemiological studies.

Micro Potentiometric Label-free Immunosensor for Glycated Hemoglobin / 分析化学

A miniaturized potentiometric label-free immunosensor based on the standard complementary metal-oxide-semiconduction transistor(CMOS) process and micro fabrication technique was developed to monitoring diabetes, which could detect the concentrations of glycated hemoglobin (HbA1c) and hemoglobin. This immunosensor includes a micro field-effect transistor based sensor chip integrated with signal readout circuit and a disposable probe electrode. The micro sensor chip was designed by our lab and fabricated by Chartered Semiconductor, Singapore. The disposable probe electrode, which was integrated with sensitive electrodes array and micro reaction pool, was deposited on polyester plastic based on micro fabrication techniques. Antibody of HbA1c and hemoglobin were immobilized on the electrode based on self assemble monolayer and gold nanoparticles. The characteristics of the electrode during modification were studied by cyclic voltammetry and electrochemical impedance technique. The response characteristic of the immunosensor was detected. HbA1c from 4 to 24 mg/L and hemoglobin from 60 to 180 mg/L can be detected by this immunosensor.

Nanopore DNA single molecule sensing method and synthetic nanopore fabrication / 国际生物医学工程杂志

Nanopore single molecule sequencing(SMS) is considered as one of the most promising third generation DNA sequencing method by virtue of fast sequencing and low cost. As the most significant part of the sequencing system, the synthetic solid nanopore has recently been the research highlight in the field of nanopore DNA sequencing because of its fine-controlled size, high reliability and wide applicability. Also, its fabrication method is currently one of the main challenges in this field. In this article, the principles of the nanopore SMS are introduced followed by the review of the difficulties and challenges in the current research stage with emphasis on the nanopore fabrication methods.

Manifestaciones impropias en la publicación científica: [revisión] / Inappropriate signs found in the scientific publication: [review]

La ocurrencia de algunas manifestaciones impropias en la producción y comunicación de resultados científicos ocurridas en el período 2004-2006, motivó la realización de esta revisión con la intención de profundizar en el conocimiento de las distintas formas en que pueden presentarse estas conductas. Se definen y comentan las formas severas como la fabricación y falsificación de datos, el plagio y otras menores o menos severas que las anteriores, como la publicación duplicada o redundante, autoría injustificada, sesgos de publicación, inexactitud en las citas bibliográfícas, entre las más importantes. Se comentan los aspectos éticos de estos problemas y se ofrecen algunos ejemplos de fraudes científicos ocurridos entre 1974 y 2006 que parecieron interesantes exponer.

Some inappropriate signs found in the production and communication of scientific results in the 2004-2006 period prompted to make this literature review, with the objective of delving into the different ways in which these misconducts may appear. The most important inappropriate signs such as data fabrication and falsification, and plagiarism as well as other minor or less severe expressions like duplicate or redundant publication, unjustified autorship, publication biases, and inaccurate bibliographic quotations were defined and discussed. Also, comments were made on the ethical aspects of these problems and some interesting examples of scientific frauds that have occured from 1974 to 2006 were provided.

Analysis of Oral State of Hansen's Patients and Denture fabrication for Pre-Prothodontic Oro-maxillofacial minor surgury / 나학회지

The purposes of this study were to investigate the oral health care conditions of patients who have Leprous disease, which is an infectious disease(Dental caries: DMF rate and DMFT rate, and Periodontal conditions: CPITN0, CPITN1 CPITN2 CPITN3 ) and the satisfaction of use of denture fabrication related to general, functional and esthetic factors among dental patients for pre-Prothodontic Oro-maxillofacial minor surgury in National sorokdo hospital. The objects for this study were 754patients(male: 453, female: 301, 60-69ages: 340, 70-79ages: 414)treated in the oral health center among Leprous disease patients with gingivitis and periodontal disease, residents in the Sorokdo from 2003, January to 2005, September. 1. The results of Dental caries investigated that the number of 60-80year-old patients group that DMF rate was 99.2% of them, DMFT rate 59.2% 2. The results of periodontal conditios investigated that the number of 60-69year-old patients group were Community Periodontal treatment need index(CPITN)0: 15, CPITN1: 2, CPITN2: 66, CPITN3: 257, and 70-79year-old patients group were CPITN0: 27, CPITN1: 1, CPITN2: 116, CPITN3: 271 (Community Periodontal treatment need index(CPITN)0 of patients who have Leprous disease means anodontia states) 3. Dental fabrication patients for pre-Prothodontic Oro-maxillofacial minor surgury have operated Lower lip reconstruction, Hypergingivotomy, Flap, Alveoloplasty, Tours ostotomy and Apicoectomny