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Summary Background Although ultraviolet (UV) phototherapy is an effective treatment for vitiligo, its effect on the risk of skin cancer remains controversial. Aim To investigate the association between UV phototherapy and skin cancer risk in patients with vitiligo. Methods A systematic review was performed for studies published before 5 May 2021 in the PubMed, Embase, Web of Science and Cochrane Library databases. The primary outcome was the association of UV phototherapy with the risk of skin cancer in patients with vitiligo. A meta-analysis with a random-effects model was conducted. Results Five retrospective cohort studies covering a total of 228 607 patients with vitiligo (110 038 who had been treated with UV phototherapy and 118 569 patients who had not) were included in the meta-analysis. The risk of nonmelanoma skin cancer [Mantel–Haenszel risk ratio (MHRR) = 0.95; 95% CI 0.44–2.05] and melanoma (MHRR = 1.11; 95% CI 0.33–3.82) did not significantly increase after phototherapy in patients with vitiligo. In the subgroup analysis, we also found no significant association between phototherapy with narrowband UVB phototherapy specifically and risk of skin cancer in patients with vitiligo. There was no significant difference in risk of skin cancer between patients from Europe and those from East Asia and the risk was not affected by the number of narrowband UVB phototherapy sessions. Conclusions The findings of this systematic review and meta-analysis suggest that UV phototherapy is a safe treatment for vitiligo with no significant risk of skin cancer.

Sulfur in coals is derived partly from original plant materials and partly from ambient fluids in the coal-forming environment. Low-sulfur (LS) coal seams (less than 1% total sulfur content), such as Tertiary coals of the Powder River Basin, USA, were deposited in an alluvial environment and the peat was not influenced by seawater. High-sulfur (HS) coal seams (greater than 3% total sulfur content) are usually associated with marine strata. Seawater influence was the primary cause of the high sulfur in the coal. For example, in the Illinois Basin, high-sulfur Herrin Coal is overlain by marine Anna Shale and Brereton Limestone, but, medium-sulfur (MS) coal (1%−3% total sulfur content) occurs in well-defined areas of the Herrin seam where the coal is directly overlain by thick (>6 m) Energy Shale. This thick nonmarine gray shale was an effective barrier to seawater diffusion into peat. Superhigh-organic-sulfur (SHOS) coals have been reported, including Rasa coal from Croatia, which has a total sulfur content of 10.8% and organic sulfur content of 10.5% (dry basis). A SHOS coal of Late Permian age from Guidin, Guizhou, China contains 9.2–10.5% total sulfur content and 8.2–9.2% organic sulfur content (dry basis). Guidin coal was derived from peat deposited on a coastal carbonate platform. Profound seawater influence and iron deficiency are key factors in the formation of SHOS Guidin coal. The sulfur content of coal macerals is highly variable. Sporinite embedded in vitrinite is higher in organic sulfur than surrounding vitrinite in Illinois Basin coals. A high efficiency of organic sulfur formation in sporinite may be resulted from abundant functional groups in sporinite precursors which reacted with active sulfur species (hydrogen sulfide, elemental sulfur and polysulfides) during early diagenesis. The thiophenic fraction of organic sulfur increases with increasing carbon content of coal. It is interpreted that organic sulfur species initially formed during early diagenesis are mostly thiols and sulfides, which convert to thiophenic compounds during coal maturation. Thus the thiophenic fraction of organic sulfur increases with coal rank.

The Reynolds number in the renal tubule is extremely low, consistent with laminar flow. Consequently, luminal flow can be described by the Hagen-Poiseuille laminar flow equation. This equation calculates the volumetric flow rate from the axial pressure gradient and flow resistance, which is dependent on the length and diameter of each renal tubule segment. Our goal was to calculate the pressure drop along each segment of the renal tubule and to determine the points of highest resistance. When the Hagen-Poiseuille equation was used for rat superficial nephrons based on known tubule flow rates, lengths, and diameters, it was found that the maximum pressure drop occurred in two segments: the thin descending limbs of Henle and the inner medullary collecting ducts. The high resistance in the thin descending limbs is due to their small diameters. The steep pressure drop observed in the inner medullary collecting ducts is due to the convergent structure of the tubules, which channels flow into fewer and fewer tubules toward the papillary tip. For short-looped nephrons, the calculated glomerular capsular pressure matched measured values, even with the high collecting duct flow rates seen in water diuresis, provided that tubule compliance was taken into account. In long-looped nephrons, the greater length of thin limb segments is likely compensated for by a larger luminal diameter. Simulation of the effect of proximal diuretics, namely acetazolamide or type 2 sodium-glucose transporter inhibitors, predicts a substantial back pressure in Bowman’s capsule, which may contribute to observed decreases in glomerular filtration rate.

In the design optimization of robot arms, the use of simulation technologies for modeling and optimizing the objective functions is still challenging. The difficulty is not only associated with the large computational cost of high-fidelity structural simulations but also linked to the reasonable compromise between the multiple conflicting objectives of robot arms. In this paper we propose a surrogate-based evolutionary optimization (SBEO) method via a global optimization approach, which incorporates the response surface method (RSM) and multi-objective evolutionary algorithm by decomposition (the differential evolution (DE ) variant) (MOEA/D-DE) to tackle the shape design optimization problem of robot arms for achieving high speed performance. The computer-aided engineering (CAE) tools such as CAE solvers, computer-aided design (CAD) Inventor, and finite element method (FEM) ANSYS are first used to produce the design and assess the performance of the robot arm. The surrogate model constructed on the basis of Box&ndash, Behnken design is then used in the MOEA/D-DE, which includes the process of selection, recombination, and mutation, to optimize the robot arm. The performance of the optimized robot arm is compared with the baseline one to validate the correctness and effectiveness of the proposed method. The results obtained for the adopted example show that the proposed method can not only significantly improve the robot arm performance and save computational cost but may also be deployed to solve other complex design optimization problems.

Current clinical methods to treat articular cartilage lesions provide temporary relief of the symptoms but fail to permanently restore the damaged tissue. Tissue engineering, using mesenchymal stem cells (MSCs) combined with scaffolds and bioactive factors, is viewed as a promising method for repairing cartilage injuries. However, current tissue engineered constructs display inferior mechanical properties compared to native articular cartilage, which could be attributed to the lack of structural organization of the extracellular matrix (ECM) of these engineered constructs in comparison to the highly oriented structure of articular cartilage ECM. We previously showed that we can guide MSCs undergoing chondrogenesis to align using microscale guidance channels on the surface of a two-dimensional (2-D) collagen scaffold, which resulted in the deposition of aligned ECM within the channels and enhanced mechanical properties of the constructs. In this study, we developed a technique to roll 2-D collagen scaffolds containing MSCs within guidance channels in order to produce a large-scale, three-dimensional (3-D) tissue engineered cartilage constructs with enhanced mechanical properties compared to current constructs. After rolling the MSC-scaffold constructs into a 3-D cylindrical structure, the constructs were cultured for 21 days under chondrogenic culture conditions. The microstructure architecture and mechanical properties of the constructs were evaluated using imaging and compressive testing. Histology and immunohistochemistry of the constructs showed extensive glycosaminoglycan (GAG) and collagen type II deposition. Second harmonic generation imaging and Picrosirius red staining indicated alignment of neo-collagen fibers within the guidance channels of the constructs. Mechanical testing indicated that constructs containing the guidance channels displayed enhanced compressive properties compared to control constructs without these channels. In conclusion, using a novel roll-up method, we have developed large scale MSC based tissue-engineered cartilage that shows microscale structural organization and enhanced compressive properties compared to current tissue engineered constructs. Statement of significance Tissue engineered cartilage constructs made with human mesenchymal stem cells (hMSCs), scaffolds and bioactive factors are a promising solution to treat cartilage defects. A major disadvantage of these constructs is their inferior mechanical properties compared to the native tissue, which is likely due to the lack of structural organization of the extracellular matrix of the engineered constructs. In this study, we developed three-dimensional (3-D) cartilage constructs from rectangular scaffold sheets containing hMSCs in micro-guidance channels and characterized their mechanical properties and metabolic requirements. The work led to a novel roll-up method to embed 2-D microscale structures in 3-D constructs. Further, micro-guidance channels incorporated within the 3-D cartilage constructs led to the production of aligned cell-produced matrix and enhanced mechanical function.

Tissue engineering is a possible method for long-term repair of cartilage lesions, but current tissue-engineered cartilage constructs have inferior mechanical properties compared to native cartilage. This problem may be due to the lack of an oriented structure in the constructs at the microscale that is present in the native tissue. In this study, we utilize contact guidance to develop constructs with microscale architecture for improved chondrogenesis and function. Stable channels of varying microscale dimensions were formed in collagen-based and polydimethylsiloxane membranes via a combination of microfabrication and soft-lithography. Human mesenchymal stem cells (MSCs) were selectively seeded in these channels. The chondrogenic potential of MSCs seeded in these channels was investigated by culturing them for 3 weeks under differentiating conditions, and then evaluating the subsequent synthesized tissue for mechanical function and by type II collagen immunohistochemistry. We demonstrate selective seeding of viable MSCs within the channels. MSC aligned and produced mature collagen fibrils along the length of the channel in smaller linear channels of widths 25-100 μm compared to larger linear channels of widths 500-1000 μm. Further, substrates with microchannels that led to cell alignment also led to superior mechanical properties compared to constructs with randomly seeded cells or selectively seeded cells in larger channels. The ultimate stress and modulus of elasticity of constructs with cells seeded in smaller channels increased by as much as fourfolds. We conclude that microscale guidance is useful to produce oriented cartilage structures with improved mechanical properties. These findings can be used to fabricate large clinically useful MSC-cartilage constructs with superior mechanical properties.

A solid oxide fuel cell (SOFC) unit is constructed with Ni-Ce0.9Gd0.1O2 – δ (GDC) as the anode, yttria-stabilised zirconia (YSZ) as the electrolyte and Pt, Ag or Cu-added La0.58Sr0.4Co0.2Fe0.8O3 – δ (LSCF)–GDC as the cathode. The current–voltage measurements are performed at 800 °C. Cu addition leads to best SOFC performance. LSCF–GDC–Cu is better than LSCF–GDC and much better than GDC as the material of the cathode interlayer. Cu content of 2 wt.-% leads to best SOFC performance. A cathode functional layer calcined at 800 °C is better than that calcined at higher temperature. Metal addition increases the O2 dissociation reactivity but results in an interfacial resistance for O transfer. A balance between the rates of O2 dissociation and interfacial O transfer is needed for best SOFC performance.

Several goals such as improving road safety and increasing transport efficiency are being pursued in intelligent transportation systems (ITS). Wireless vehicular communication is one technology to achieve these goals. Conducting vehicular experiments on the roads is an approach to studying the effectiveness of wireless vehicular communication. However, such an approach is costly, hard-to-control (repeat), dangerous, and infeasible when many vehicles and people are involved in the field trial. In contrast, the simulation approach does not have these problems. It is a very useful approach and complements the field trial approach. This paper presents NCTUns, an open source integrated simulation platform, for wireless vehicular communication network researches. This tool tightly integrates network and traffic simulations and provides a fast feedback loop between them. Therefore, a simulated vehicle can quickly change its driving behavior such as moving speed and direction when it receives a message from the wireless vehicular communication network. This capability is required by several novel ITS applications such as active collision avoidance systems. In this paper, we present the design, implementation, validation, and performance of this tool.

NCTUns is a network simulator running on Linux. It has several unique advantages over traditional network simulators. This paper presents the novel design and implementation of its simulation engine. This paper focuses on how to combine the kernel re-entering and discrete-event simulation methodologies to execute simulations quickly. The performance and scalability of NCTUns are also presented and discussed.

Shanxi province, located in the center of China, is the biggest coal base of China. There are five coal-forming periods in Shanxi province: Late Carboniferous (Taiyuan Formation), Early Permian (Shanxi Formation), Middle Jurassic (Datong Formation), Tertiary (Taxigou Formation), and Quaternary. Hundred and ten coal samples and a peat sample from Shanxi province were collected and the contents of 20 potentially hazardous trace elements (PHTEs) (As, B, Ba, Cd, Cl, Co, Cr, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se, Th, U, V and Zn) in these samples were determined by instrumental neutron activation analysis, atomic absorption spectrometry, cold-vapor atomic absorption spectrometry, ion chromatography spectrometry, and wet chemical analysis. The result shows that the brown coals are enriched in As, Ba, Cd, Cr, Cu, F and Zn compared with the bituminous coals and anthracite, whereas the bituminous coals are enriched in B, Cl, Hg, and the anthracite is enriched in Cl, Hg, U and V. A comparison with world averages and crustal abundances (Clarke values) shows that the Quaternary peat is highly enriched in As and Mo, Tertiary brown coals are highly enriched in Cd, Middle Jurassic coals, Early Permian coals and Late Carboniferous coals are enriched in Hg. According to the coal ranks, the bituminous coals are highly enriched in Hg, whereas Cd, F and Th show low enrichments, and the anthracite is also highly enriched in Hg and low enrichment in Th. The concentrations of Cd, F, Hg and Th in Shanxi coals are more than world arithmetic means of concentrations for the corresponding elements. Comparing with the United States coals, Shanxi coals show higher concentrations of Cd, Hg, Pb, Se and Th. Most of Shanxi coals contain lower concentrations of PHTEs.

Spatially-resolved electroluminescence (EL) images in the triple-junction InGaP/InGaAs/Ge solar cell have been investigated to demonstrate the subcell coupling effect. Upon irradiating the infrared light with an energy below bandgap of the active layer in the top subcell, but above that in the middle subcell, the EL of the top subcell quenches. By analysis of EL intensity as a function of irradiation level, it is found that the coupled p-n junction structure and the photovoltaic effect are responsible for the observed EL quenching. With optical coupling and photoswitching effects in the multi-junction diode, a concept of infrared image sensors is proposed.

Renal aquaporins. Aquaporins (AQPs) are a newly recognized family of transmembrane proteins that function as molecular water channels. At least four aquaporins are expressed in the kidney where they mediate rapid water transport across water-permeable epithelia and play critical roles in urinary concentrating and diluting processes. AQP1 is constitutively expressed at extremely high levels in the proximal tubule and descending limb of Henle's loop. AQP2, -3 and -4 are expressed predominantly in the collecting duct system. AQP2 is the predominant water channel in the apical plasma membrane and AQP3 and -4 are found in the basolateral plasma membrane. Short-term regulation of collecting duct water permeability by vasopressin is largely a consequence of regulated trafficking of AQP2-containing vesicles to and from the apical plasma membrane.

Previous studies have demonstrated that both the V2-receptor agonist, 1-desamino-8-D-arginine vasopressin (dDAVP), and the V1a-receptor agonist, [Phe2, Orn8]vasotocin (PO-VT), increase intracellular calcium concentration ([Ca2+]i) in the rat inner medullary collecting duct (IMCD). The present studies were done to clarify the receptor subtype(s) responsible for calcium mobilization. Measurements of [Ca2+]i, using fura 2 in microdissected IMCD segments, confirmed that arginine vasopressin (AVP), dDAVP, and PO-VT stimulate an increase in [Ca2+]i and that the response to all three agents could be blocked by the specific V2-receptor antagonist, [d(CH2)5(1),D-Ile2, Ile4, Arg8]vasopressin (II-VP). These results would suggest that all three agents acted through the V2 receptor. Furthermore, we showed that PO-VT increased cAMP production in IMCD suspensions and water permeability in isolated perfused tubules. These responses were also blocked by II-VP, indicating that PO-VT is also a V2 agonist in the IMCD. Finally, we utilized the quantitative reverse transcription-polymerase chain reaction technique of Wiesner (Nucleic Acids Res. 20: 5863-5864, 1992) to evaluate V1a and V2 mRNA levels in rat collecting duct. In terminal IMCD, we estimated > 30 copies/cell for V2 receptor mRNA but less than 1 copy/cell of V1a receptor mRNA, thus there is littler or no V1a mRNA expression in the terminal IMCD. These results suggest that calcium mobilization in response to vasopressin analogues is associated with the V2 receptor and that the V2 receptor is linked to both adenylyl cyclase and calcium mobilization in the rat IMCD.

The urine concentrating effect of the mammalian renal inner medulla has been attributed to countercurrent multiplication of a transepithelial osmotic difference arising from passive absorption of NaCl from thin ascending limbs of long loops of Henle. This study assesses, both mathematically and experimentally, whether the permeability criteria for effective function of this passive hypothesis are consistent with transport properties measured in long loops of Henle of chinchilla. Mathematical simulations incorporating loop of Henle transepithelial permeabilities idealized for the passive hypothesis generated a steep inner medullary osmotic gradient, confirming the fundamental feasibility of the passive hypothesis. However, when permeabilities measured in chinchilla were used, no inner medullary gradient was generated. A key parameter in the apparent failure of the passive hypothesis is the long-loop descending limb (LDL) urea permeability, which must be small to prevent significant transepithelial urea flux into inner medullary LDL. Consequently, experiments in isolated perfused thin LDL were conducted to determine whether the urea permeability may be lower under conditions more nearly resembling those in the inner medulla. LDL segments were dissected from 30–70% of the distance along the inner medullary axis of the chinchilla kidney. The factors tested were NaCl concentration (125–400 mM in perfusate and bath), urea concentration (5–500 mM in perfusate and bath), calcium concentration (2–8 mM in perfusate and bath), and protamine concentration (300 micrograms/ml in perfusate). None of these factors significantly altered the measured urea permeability, which exceeded 20 x 10(-5) cm/s for all conditions. Simulation results show that this moderately high urea permeability in LDL is an order of magnitude too high for effective operation of the passive countercurrent multiplier.

Many types of backfill are used as supporting technique in underground mines to optimize ground control stability and to minimize environmental problem at the surface. In theory cemented rockfill can yield optimum strength resistance, yet it is the least implemented in practice due to difficulties related to laboratory analysis of coarse particles in the material. This paper focuses on finding an appropriate protocol to use nondestructive testing techniques to characterize a cement-based material and to study the evolution of the properties during a curing period of 120 days. The testing techniques are the electrical resistivity and sonic methods. The resistivity technique highlights the changes in resistivity caused by hydration processes and the bond developing between the backfill constituents. The sonic technique measures the P and S waves. Knowing the velocity of the waves, changes of the geotechnical properties can be evaluated using known relationships between velocities and mechanical properties. Overall the mechanical strength can be indirectly monitored by these two techniques. Both techniques are complementary to one another and their joint application should improve the interpretation of strength. A concrete sample was made to test these two techniques on a slightly heterogeneous material. The experiment shows that the techniques are sensitive to the physical property changes and they enable monitoring of hardening and strength development. The far-reaching outcome of this research could help assess the properties of different compositions of mining rockfills in the laboratory before using them in mines. Alternatively, these techniques may be used on other cement-based material with coarser particles.

Analysis of nonhomologous recombination events at the Ig loci revealed that a four base sequence, 5'-CCAG-3', or its complement, 5'-CTGG-3', is present within seven nucleotides in 12 of the 13 examined recombination breakpoints. Statistical analysis of the data indicates that this occurrence has a probability of less than 10(-5) of occurring by chance. This sequence is infrequently found at nonhomologous recombination breakpoints in non-Ig sequences, suggesting that its contribution may be either Ig- or B cell-specific. Intriguingly, this tetranucleotide is also found to be associated with the breakpoints of VH gene replacement and isotype switching, suggesting that common pathways may be involved in all three B cell processes.

Conventional univariate and multivariate analysis of covariance (ANCOVA and MANCOVA) are commonly used to investigate time trends in contaminant levels in fish tissues. Both procedures require that years do not differ in their residual variances, covariances, and regression parameters. These requirements were not met in many data sets. A multivariate procedure that does not have these requirements was used to reanalyse contaminant concentration trends in Canadian cod data collected between 1977 and 1985.

The vasopressin-regulated urea carrier and the vasopressin-regulated water channel are distinct transporters present in the apical membrane of the inner medullary collecting duct (IMCD) cells. To assess whether these transporters may be activated by common mechanisms, we investigated the time course of increase of urea and water permeability in response to vasopressin in isolated perfused terminal IMCD segments. The permeability responses were determined through the use of a specially designed continuous-flow fluorometer for rapid analysis of collected tubule fluid samples. The time courses of activation of the two transporters by vasopressin were virtually identical. Both urea and water permeability displayed a rapid initial increase for the first 10 min followed by a slower secondary response lasting at least 30 additional min. The lag periods between vasopressin addition and the initial rise in permeability were the same for urea (34.2 +/- 8.8 s) and water (34.8 +/- 8.9 s) transport activation. Furthermore, the initial rate of permeability increase (normalized by the total increase) was not significantly different for the two transport processes. The lag periods for the increase in urea permeability in response to 8-bromoadenosine 3',5'-cyclic monophosphate and vasopressin were not significantly different. The results are consistent with the view that the rate-limiting step in vasopressin-induced activation is the same for both the urea carrier and water channel and may lie at a step beyond generation of adenosine 3',5'-cyclic monophosphate.

NCTUns is a high-fidelity network simulator and emulator. By using a novel kernel re-entering simulation methodology, it provides many unique advantages over traditional network simulators and emulators. For this reason, since its public release on November 1, 2002, as of February 2, 2009, more than 13,838 people from 130 countries in the world have registered at its web site to download it and these numbers are still fast increasing. NCTUns is open-source and runs on Linux. It can simulate many different types of networks. In this paper, we will present its supports for wireless vehicular network researches. In particular, it supports IEEE 802.11(p)/1609 standards, which are proposed for wireless vehicular networks. More information about this tool is available at its web site at (http://NSL.csie.nctu.edu.tw/nctuns.html).

Stent implantation has been reported to facilitate liberation from mechanical ventilation in patients with respiratory failure due to central airway disease. The present retrospective cohort study sought to evaluate the risk and benefit of stent implantation via bronchoscopy without fluoroscopic guidance in mechanically ventilated patients. From July 2001 to September 2006, 26 patients with acute respiratory failure were recruited. A bronchoscope was inserted through a mouth guard into the space between the tracheal wall and the endotracheal tube. A guide wire was inserted via the flexible bronchoscope to the lesion site. The bronchoscope was reintroduced through the endotracheal tube. Under bronchoscopic visualisation, the delivery catheter was advanced over the guide wire to deploy the stent. These procedures were successfully performed in 26 patients, with 22 stents placed in the trachea and seven in the main bronchus. Of the 26 patients, 14 (53.8%) became ventilator independent during their stay in the intensive care unit. Severe pneumonia was the most common cause, in seven (58.3%) out of 12 patients, for continued ventilator dependence after stenting. Granulation tissue formation was found in seven patients during the follow-up period. It is concluded that metallic stents can be safely implanted without fluoroscopic guidance in patients with respiratory failure, to facilitate ventilator independence.

Optically-pumped, single-mode stimulated emission was observed on GaN triangular submicron-cavity bounded by {10-10} facets. FDTD analysis indicates a high-Q factor (103) resultant from material's dispersion effect near the bandedge.

An IVC (Inter-vehicle communication) network is a type of mobile ad hoc networks (MANET) in which high-speed vehicles send, receive, and forward packets via other vehicles on the roads. An IVC network can provide useful applications in future Intelligent Transportation Systems. However, due to frequent network topology changes, a routing path in an IVC network breaks easily. As such, a routing protocol proposed for general MANET (e.g., AODV) performs poorly in IVC networks. To address this problem, we designed and implemented an intelligent flooding-based routing protocol and conducted several field trials to evaluate its performance on the roads. Results obtained from field trials show that (1) our protocol outperforms AODV significantly on IVC networks, and (2) our protocol can make many useful services such as email, ftp, web, video conferencing, and video broadcasting applicable on IVC networks for vehicle users.

Only a few studies have concentrated on elements such as thallium (TI). Uranium (U) has been studied as a radionuclide of concern in food and the environment. Foodstuffs contain 10-100 ng U{center_dot}{sup -1} with vegetables and cereals contributing most heavily to the daily intake of ca 1.5 ug U. Between 10-30% of ingested U is absorbed, with most being stored in bone. Rainbow trout (onchorynchus mykiss) and longnose sucker (Catostomus catostomus) from a lake with naturally high radioactivity contained < 5 ng U{center_dot}g{sup -1} in the flesh. Trout bone contained 40 ng U{center_dot}g{sup -1}. Higher tissue U concentrations occurred in fish from areas receiving U mining wastes. Bioconcentration factors for bone and flesh were estimated to be low, 118 and 14.7, respectively. This paper describes the Inductively coupled plasma-mass spectrometry (ICP-MS) determination of Tl and U in digestive gland tissue from lobsters captured in the vicinity of Belledune Harbor, New Brunswick, Canada. The harbor is the site of a lead smelter, a fertilizer plant, and a coal-fired power station (the latter due to enter production in late 1993) and thus has the potential of adding significant amounts of Tl to the local marine environment. The accumulation of Tl from watermore » by marine shellfish is low, at least for bivalves, and the accumulated Tl is eliminated in a number of days when the animals are transferred to clean water. Bioconcentration factors for U in finfish ranged from 0.4-17 for larger species. However, because of the high concentrations of various trace elements in lobster digestive gland, its desirability as a foodstuff, and its relatively large size (approximately 20% of the edible tissue yield), we have investigated Tl and U concentrations and {sup 235U}/{sup 238U} ratios in it. 15 refs., 1 fig., 3 tabs.« less

The purpose of this study is to detect the median nerve lesions at wrist in professional cyclists. Totally 14 national representative cyclists were included. Each subject was questionnaired and asked to draw their site of hand discomfort, followed by hand grip power test with grasp, lateral pinch and palmar pinch. A control group of 30 medical students were also tested for grip power. Electrodiagnostic examination of bilateral median nerves was then done on every cyclist, including motor and sensory nerve conduction studies, and needle EMG on abductor pollicis brevis and other associated muscles. Of the 28 hands in 14 cyclists, 7 in 4 subjects had neurologic symptoms related to median nerve, and 5 in 4 subjects had abnormal electrodiagnostic examinations. The grip power was significantly better in cyclists than in control. The prevalence of median nerve lesions at wrist in cyclists, although usually mild, was substantially higher than expected. Electrodiagnosis can be used as a sensitive detector for neuropathy even at subclinical stage. It is suggested that cyclists and trainers should be aware of the median nerve lesion during cycling and training in order to take early preventive, diagnostic and therapeutic procedures.