Tiny Holes Research Articles

Optic pit with macular schisis: subtle but discernible

Sir, I just read the case report on ‘idiopathic macular hole' in a child in the April 2012 issue of EYE journal.1 I was surprised to see that an open-and-shut case of optic disc pit with macular schisis has been described as ‘idiopathic' in this report.2 There is no full-thickness macular hole in the reported case; what is reported as a macular hole is actually a well-described outer retinal dehiscence (Figure 2 of the article).2, 3 Even if the pits were invisible (it is clearly visible in Figure 1 at 3:00 meridian), the tell-tale schisis on OCT gives the clue to the presence of an occult optic disc dysplasia as the cause of maculopathy.4 Therefore, this is certainly not the first report of an ‘idiopathic' macular hole in a child, as there was neither a full-thickness hole at presentation nor was the pathology idiopathic. In fact, the surgeon created an iatrogenic macular hole (Figure 3) in this patient, a possibility that we have described previously.3 However, I agree with the surgical management of the maculopathy and suspect that the tiny postoperative macular hole might have closed subsequently.

Using high pressure processing (HPP) to pretreat sugarcane bagasse

High pressure processing (HPP) technology was used to modify the structural composition of sugarcane bagasse. The effect of pressure (0, 150 and 250MPa), time (5 and 10min) and temperature (25 and 50°C) as well as the addition of phosphoric acid, sulfuric acid and NaOH during the HPP treatment were assessed in terms of compositional analysis of the lignocellulosic fraction, structural changes and crystallinity of the bagasse. The effect of HPP pretreatment on the bagasse structure was also evaluated on the efficiency of the enzymatic hydrolysis of bagasse. Results showed that 68.62 and 45.84% of the hemicellulose fraction was degraded by pretreating at 250MPa with sulfuric and phosphoric acids, respectively. The removal of lignin (54.10%) was higher with the HPP-NaOH treatment. The compacted lignocellulosic structure of the raw bagasse was modified by the HPP treatments and showed few cracks, tiny holes and some fragments flaked off from the surface. Structural changes were higher at 250MPa and 50°C. The X ray diffraction (XRD) patterns of the raw bagasse showed a major diffraction peak of the cellulose crystallographic 2θ planes ranging between 22 and 23°. The distribution of the crystalline structure of cellulose was affected by increasing the pressure level. The HPP treatment combined with NaOH 2% led to the higher glucose yield (25g/L) compared to the combination of HPP with water and acids (>5g/L). Results from this work suggest that HPP technology may be used to pretreat sugarcane bagasse.

Development of a glass GEM

Gas electron multipliers (GEMs) apply the concept of gas amplification inside many tiny holes, realizing robust and high-gain proportional counters. However, the polyimide substrate of GEMs prevents them from being used in sealed detector applications. We have fabricated and tested glass GEMs (G-GEMs) with substrates made of photosensitive glass material from the Hoya Corporation. We fabricated G-GEMs with several different hole diameters and thicknesses and successfully operated test G-GEMs with a 100×100mm2 effective area. The uniformity of our G-GEMs was good, and the energy resolution for 5.9keV X-rays was 18.8% under uniform irradiation of the entire effective area. A gas gain by the G-GEMs of up to 6700 was confirmed with a gas mixture of Ar (70%)+CH4 (30%). X-ray imaging using the charge division readout method was demonstrated.

Interaction of micro-discharges in heptane with metallic multi-layers

Interaction of discharges in heptane with magnetron-sputtered thin films made of aluminum, copper or iron is studied in a pin-to-plate configuration. The behavior of discharges on thin films can be used to better understand the interaction of discharges with given surfaces and it might also improve the reproducibility of the impacts in order to better control their shape. Single layers and bilayers of metals are characterized after impact by SEM, AFM, micro-EDX and nano-SIMS analyses. Discharges last typically for a few hundreds of nanoseconds and dissipated energies range between 1 and 100mJ. We show that at low impact energy, copper and aluminum are heated and stretched by surface stress. At intermediate energy, melting occurs, leading to the synthesis of external beads by Marangoni's convection. At high energy, the shape of the impact is defined by the pressure release when the discharge stops. When iron is deposited onto silicon, dewetting is an important mechanism. The columnar structure of the deposit may have two distinct roles. On the one hand, gases trapped in intercolumnar boundaries can produce tiny holes. On the other hand, the shock wave can abrade the outermost and less cohesive part of the film if it is made of columns separated by large porosities.

Electrodepositing Ir Film at Constant Current in NaCl-KCl Molten Salts

In this study, the dense and well-integrated Ir films were electrodeposited on Pt substrate at a constant current process in the NaCl-KCl molten salt system containing IrCl3. The morphology and constitution of the Ir films at different process conditions were examined by scanning electron microscope (SEM), energy dispersive spectroscope (EDS) and X-ray diffraction (XRD) respectively. The results showed that IrCl3 concentration had significantly influenced the surface morphology of the Ir film. The particles of the deposition film surface became lager with increasing the fraction of IrCl3 and gradually decreased with increasing the temperature. However, the film quality decreased due to the formation of some tiny holes when further increasing the temperature. The particle size decreased gradually with the increase of deposition current density. The addition of CsCl could not only reduce the molten salt temperature but also increase the deposition rate of Ir.

Catamenial pneumothorax: a rare entity? Report of 5 cases and review of the literature.

Spontaneous recurrent pneumothorax during menstruation is reported as catamenial pneumothorax. It is encountered in 3-6% of spontaneous pneumothorax cases among menstruating women. The percentage among women referred for surgery is significantly higher (25-30%). Although it usually involves the right-side (85-95%) it can be left-sided or bilateral. It is associated with diaphragmatic perforations and/or thoracic endometriosis. There is pelvic endometriosis in up to 30-51% of cases. The lesions that are not always found may present as small or larger holes at the central tendon of the diaphragm, as red, blueberry, brown spots or larger nodules at the diaphragm, the visceral or parietal pleura. Lesion histology may reveal endometriosis. We present 5 cases of catamenial pneumothorax treated surgically during the last 6 years. Five women, with a mean age of 34+/-9.9 years (median 38, range, 19-45 years) presented with right-sided recurrent catamenial pneumothorax. In 3 patients diaphragmatic perforation(s) were found; perforation suturing (n=1), and diaphragmatic plication reinforced with bovine pericardial patch (n=1) were performed. All patients underwent atypical resection of upper and/or middle lobe segments of lung parenchyma that appeared abnormal (haemorrhagic/emphysematous or blebs). Four patients underwent pleurodesis and 1 patient underwent pleurectomy. Four interventions were performed through video assisted thoracoscopic surgery, while diaphragmatic plication was performed through a video assisted mini-thoracotomy. Histology did not reveal endometriosis tissue. The postoperative course was uneventful. The patients were extubated in theatre and were discharged home at a mean of 7+/-4 days (median 6 days, range, 4-14 days). Two of them received hormonal therapy [Gonadotropin Releasing Hormone (GnRH) analogue] postoperatively. At a follow-up of 14.16 patient-years (mean 2.83+/-1.08 years, range, 1.33-3.83 years) there was recurrence, 6.5 months postoperatively, in one patient that had not undergone closure of a tiny diaphragmatic hole and had not received hormonal treatment postoperatively. She was treated medically (amenorrhea for 6 months with GnRH analogue) and had no further recurrences (in 3.3 years). Surgery is the treatment of choice of catamenial pneumothorax. It should aim to complete management of all lesions. The most common complication is recurrence. Early diagnosis and multidisciplinary treatment including hormonal therapy may be beneficial in high risk patients.

Experimental Research on Damage of Rubberized Cement-Soil

In order to analyze rubber powder influencing on cement-soil, axial compression stress-strain curves and a series of damage relationship curves are obtained by unconfined compression test and circulating load-unload test. The damage process of rubberized cement-soil could be divided into four phases including internal tiny crack closing, cracking, crack stable extension and crack unstable extension. Rubber powder increased stress and strain threshold values of cement-soil. 10% was the best rubber powder content. Rubber powder can impede cement-soil inner tiny holes and crakes to occur and develop, so that damage resistance and deformation capability are improved.

복강경수술 훈련용 담낭 절제술 시뮬레이션 개발

Laparoscopic surgery is a surgical procedure which uses long laparoscopic instruments through tiny holes in abdomen while watching images from a laparoscopic camera through umbilicus. Laparoscopic surgeries have many advantages rather than open surgeries, however it is hard to learn the surgical skills for laparoscopic surgery. Recently, some virtual simulation systems for laparoscopic surgery are developed to train novice surgeons or resident surgeons. In this study, we introduce the techniques that we developed for laparoscopic surgical training simulator for cholecystectomy (gallbladder removal), which is one of the most frequently performed by laparoscopic surgery. The techniques for cholecystectomy simulation include modeling of human organs (liver, gallbladder, bile ducts, etc.), real-time deformable body calculation, realistic 3D visualization of surgical scene, high-fidelity haptic rendering and haptic device technology, and so on. We propose each simulation technique for the laparoscopic cholecystectomy procedures such as indentifying cystic duct and cystic artery to clamp and cut, dissecting connective tissues between the gallbladder and liver. In this paper, we describe the techniques and discuss about the results of the proposed cholecystectomy simulation for laparoscopic surgical training.

A Method for Probing the Liquid–Liquid Interface

A simple method for probing the interface of a liquid–liquid system is proposed. Two immiscible liquids are chosen and one is a UV curable monomer. When the two liquids meet, a curved interface is formed. Such an interface can be fixed once the liquid monomer has been solidified by UV exposure. After removing the uncured liquid, the solidified surface, which records the information of the liquid–liquid interface, can be observed directly. Our result shows that the surface of the cured monomer is smooth as the liquid–liquid contact time is less than 12 h. As the contact time is long enough, the surface becomes rough. However, the roughness does not go worse when the contact time is over 1000 h. Atomic force microscope (AFM) shows that the roughness of the interface is due to the formed tiny holes and bumps. Detailed results are given and the impact of surface roughness on the device performance, such as liquid lenses, is analyzed.

Wavefront shaping of infrared light through a subwavelength hole

Light passing through a subwavelength hole in an opaque plate is a fundamental concern in both optical science and applications. Using both simulations and experiments, we show that, when a subwavelength hole in a silver thin film is surrounded by well-designed patterns of grooves, the wavefront of the infrared light through it can be shaped into a preset complicated pattern such as a Latin letter ‘L’ or ‘O’ at a given position instead of being diffracted in all directions. The design is created via the surface-wave-holography method, which allows direct determination of the surface plasmonic structure for a given wavefront-engineering functionality without the need to solve complex inverse problems. The results will deepen current understanding of this enduring issue and will find applications in many fields such as wave manipulation and sensing. Researchers have shown how passing a light beam through a tiny hole in a thin metallic film can be used to modify the beam's shape. Modifying light as it passes through a material is a key functionality for many optical devices. Holes in metal films are known to enhance light transmission through plasmonic effects—collective motions of electrons on the metal surface. Zhi-Yuan Li and colleagues at the Institute of Physics, Chinese Academy of Sciences, China, showed that patterning the surface of the metal film with grooves allows the light emerging on the other side to take almost any shape. Such functionality could find a wide range of applications in holography or optical imaging.

Detection and characterization of the spatial inhibition potential in electroperforated sheet materials

The spatial distribution of tiny holes in sheet materials generated by means of electrical discharges is investigated using spatial statistics techniques. It is shown that whereas the holes appear to be randomly distributed according to a Poisson point pattern, there is in fact a small region around each hole in which the generation of a new one is statistically inhibited as a consequence of the lower impedance path offered by the already made hole. The resulting pattern is known in spatial statistics as a point process with a soft-core inhibition potential, which can be characterized using the pair correlation function. ► Analysis of electroperforated sheet materials using spatial statistics. ► Deviation from Complete Spatial Randomness (CSR) is detected. ► The inhibition potential is characterized using functional summary estimators.

Tiny holes with great promise

Sensors that combine solid-state nanopores and nanowire field-effect transistors can be used to detect single DNA molecules quickly and with high sensitivity.

Treatment of Dye Wastewater by Using a Hybrid Gas/Liquid Pulsed Discharge Plasma Reactor

A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles. The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel. The effects of the peak pulse voltage, additive gas varieties, gas bubbling rate, solution conductivity and TiO2 addition were investigated. The results showed that this reactor was effective for dye wastewater treatment. The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied. Under the studied conditions, 97% of Acid Orange II in aqueous solution was effectively decolored with additive oxygen gas, which was 51% higher than that with argon gas, and the increasing O2 bubbling rate also benefited the decoloration of dye wastewater. Water conductivity had a small effect on the level of decoloration. Catalysis of TiO2 could be induced by the pulsed discharge plasma and addition of TiO2 aided the decoloration of Acid Orange II.

Carbon-coated mesoporous SnO2 nanospheres as anode material for lithium ion batteries

In this paper mesoporous SnO 2 nanospheres with an average diameter of about 83 nm, composed of many tiny primary particles (∼10 nm) and holes, are synthesized on a large scale by a simple hydrothermal route. The as-prepared mesoporous SnO 2 nanospheres were uniformly coated with carbon by a further hydrothermal treatment in glucose aqueous solution. As anode materials for lithium-ion batteries, the core–shell SnO 2 /C nanocomposites exhibit a markedly improved cycling performance.

Aerodynamic Pressure Fluctuations Associated With Flow-Induced Vibration of the Head Gimbals Assembly Inside a Hard Disk Drive

This paper presents an experimental investigation and numerical simulation on the spectrum-spatial characteristics of aerodynamic pressure fluctuations around the head gimbals assembly (HGA) in a working hard disk drive (HDD). The pressure fluctuations are measured through tiny holes on the HDD top cover above the HGA. The positioning error signal and servo system sensitivity in the working HDD are measured as well to evaluate the slider off-track vibration. Comparisons between the spectra of pressure fluctuations and the slider off-track vibration show that, the pressure fluctuations around the HGA are highly associated with the slider off-track vibration in terms of principal peaks in the spectra, especially at 1.83 kHz and 2.54 kHz. The results also show that the spatial coherence of pressure fluctuation around the HGA remains high at frequencies around the principal peaks in the spectra, which has been further confirmed by the numerical simulation based on a two-dimensional large eddy simulation model. It is concluded that the flow-induced HGA vibrations in an HDD can be detected and evaluated through the pressure fluctuations by a sensor around the HGA.

Review on prion diseases in animals with emphasis to Bovine Spongiform Encephalopathy

Prion diseases are known as Transmissible Spongiform Encephalopathies (TSE). These are degenerative brain disorders characterized by tiny microscopic holes that give the brain 'spongy' appearance. The causative agent is proteinaceous infective particle called prion. Prion diseases affect a variety of mammals including humans. The disease is transmitted by contaminated food or feed containing prion protein. In animals the diseases caused by prions are Scrapie, Bovine Spongiform Encephalopathy (BSE), Transmissible Mink Encephalopathy (TME), Chronic Wasting Disease (CWD), Feline Spongiform Encephalopathy (FSE) and exotic Engulate Encephalopathy (EUE). Currently the only reliable test is histo-pathological examination of tissues. Control measures are surveillance, culling sick animals and banning specified risk materials. In India no case of BSE has been reported so far but the disease warrants constant monitoring and surveillance if once introduced or imported would be a herculean task to eradicate it.

S041024 高速遠心成形法によるコモンレールディーゼル用の微細で複雑な穴配置を持つノズル製造技術の開発

S041024 高速遠心成形法によるコモンレールディーゼル用の微細で複雑な穴配置を持つノズル製造技術の開発

Study on fish allergen microcapsules and controlled-release kinetics

The aim is to prepare a kind of sodium alginate microcapsules which could slowly release fish allergens.The spherical alginate microcapsules were prepared by the ionotropic gelation method and the microcapsules were formed by adding sodium alginate into aqueous solution containing calcium chloride.The prepared microcapsules were characterized by FTIR,DSC and SEM methods.The releasing mechanism of parvalbumin from the microcapsules was established based on equation fitting of release kinetics model.Parvalbumin could be embedded into alginate microcapsules.The entrapment efficiency was 69.24% while the loading ratio was 21.06%.The surface of microcapsules which had plenty of tiny holes was rough.The result of protein release in vitro showed that parvalbumin released rapidly in the first 5 hours,and then gradually achieved maximum.The release kinetics model suited Higuchi equation and Ritger-Peppas equation well.Fish allergen could be entrapped by sodium alginate,meanwhile allergen controlled-release was achieved.The mechanism fits with skeleton erosion in addition to protein diffusion mechanism.

Sensitive Quantitative Predictions of MHC Binding Peptides and Fragment Based Peptide Vaccines from Taenia crassiceps

Taenia crassiceps is a member of the Taenia genus. It is a tapeworm. It is related to Taenia solium, the pork tapeworm, and to Taenia saginata, the beef tapeworm. Its larvae eat tiny holes in the human retina, eventually detaching it. The life cycle is when an adult lays eggs inside a wild canine. Peptide fragments of antigen protein can be used to select nonamers for use in rational vaccine design and to increase the understanding of roles of the immune system in infectious diseases. Analysis shows MHC class II binding peptides of antigen protein from Taenia crassiceps are important determinant for protection of host form parasitic infection. In this assay, we used PSSM and SVM algorithms for antigen design and predicted the binding affinity of antigen protein having 72 amino acids, which shows 64 nonamers. Binding ability prediction of antigen peptides to major histocompatibility complex (MHC) class I & II molecules is important in vaccine development from Taenia crassiceps.

용해, 확산, 분출의 정의와 교과서 서술에 대한 재고찰

선행연구에 의하면 많은 중 고등학교 학생들과 교사들이 용해와 확산, 확산과 분출을 잘 구분하지 못한다고 하므로 본 연구에서는 이 용어들의 정의로부터 각 개념들을 서로 구분하는 것이 가능한지 알아보고자 하였다. 이를 위해 현재 과학자들이 합의하고 있는 것으로 생각되는 용어의 정의를 IUPAC의 Gold Book과 대학 물리화학 교재로부터 조사하여 비교하였다. 그리고 현행 중 고등학교 교과서 및 대학 일반화학 교재에 서술된 정의를 조사하여 학생들과 교사들이 혼란을 느낄 수 있는 문제점을 파악하고 그 개선점을 알아보고자 하였다. 그 결과 용해는 두 상이 혼합되어 하나의 상이 되는 것임에 비해 확산은 농도 차를 없애는 방향으로 물질이 이동하는 것이므로 서로 구분 가능하다고 생각된다. 그러나 중.고등학교 교과서와 대학 일반화학 교재에서도 대부분 확산을 농도 차에 의한 것으로 명확하게 서술하지 않았는데 이 1022 박종윤를 강조해서 서술할 필요가 있다. 분출은 용기 벽면의 아주 작은 구멍을 통해 기체 입자가 충돌 없이 빠져나가는 것이므로 기체 확산과 분명히 구분되지만 고등학교 교과서에서 분출의 정의를 제시한 교과서는 거의 없었다. 【Previous studies showed that many secondary school students and teachers have difficulties in distinguishing the phenomena of dissolution and diffusion, as well as the phenomena of diffusion and effusion. In this study, currently accepted term definitions of dissolution, diffusion and effusion were searched from the IUPAC Gold Book and the physical chemistry textbooks, and the points to differentiate the definitions were sought. Also, the term definitions of these three phenomena in the secondary school text books and the college general chemistry textbooks were surveyed and compared to the currently accepted definitions. It was found that dissolution is formation of one new phase from mixing two phases, while diffusion is the migration of matter down from the gradient. The concentration is considered to be a key point to distinguish diffusion from the dissolution. However, the gradient was not mentioned in the definitions of diffusion in most of the secondary school textbooks and the college general chemistry textbooks. Effusion is differentiated from diffusion by the gas molecules escaping from the container through a tiny hole without collision. The definition of effusion was not found in most of the secondary school textbooks.】