Embedded 3D printing of porous silicon orbital implants and its surface modification / 南方医科大学学报

OBJECTIVE@#To prepare customized porous silicone orbital implants using embedded 3D printing and assess the effect of surface modification on the properties of the implants.@*METHODS@#The transparency, fluidity and rheological properties of the supporting media were tested to determine the optimal printing parameters of silicone. The morphological changes of silicone after modification were analyzed by scanning electron microscopy, and the hydrophilicity and hydrophobicity of silicone surface were evaluated by measuring the water contact angle. The compression modulus of porous silicone was measured using compression test. Porcine aortic endothelial cells (PAOECs) were co-cultured with porous silicone scaffolds for 1, 3 and 5 days to test the biocompatibility of silicone. The local inflammatory response to subcutaneous porous silicone implants was evaluated in rats.@*RESULTS@#The optimal printing parameters of silicone orbital implants were determined as the following: supporting medium 4% (mass ratio), printing pressure 1.0 bar and printing speed 6 mm/s. Scanning electron microscopy showed that the silicone surface was successfully modified with polydopamine and collagen, which significantly improved hydrophilicity of the silicone surface (P < 0.05) without causing significant changes in the compression modulus (P > 0.05). The modified porous silicone scaffold had no obvious cytotoxicity and obviously promoted adhesion and proliferation of PAOECs (P < 0.05). In rats bearing the subcutaneous implants, no obvious inflammation was observed in the local tissue.@*CONCLUSION@#Poprous silicone orbital implants with uniform pores can be prepared using embedded 3D printing technology, and surface modification obviously improves hydrophilicity and biocompatibility of the silicone implants for potential clinical application.

Research on friction and wear behaviors of silicon-lithium spray coating on zirconia ceramics / 北京大学学报(医学版)

OBJECTIVE@#To study microstructure, friction and wear behaviors of silicon-lithium spray coating on the surface of zirconia ceramics and to preliminarily evaluate its esthetic so as to provide support and guidance for the clinical application.@*METHODS@#Zirconia ceramic specimens were randomly divided into three groups: coating group (two subgroups), polishing group (two subgroups), and glazing group (four subgroups), with 10 samples in each subgroup. The two subgroups of coating group were the zirconia ceramics with the untreated and preliminary polishing surfaces sprayed with silicon-lithium coating, respectively. The two subgroups of polishing group were preliminary polishing and fine polishing of zirconia ceramics, respectively. The four subgroups of glazing group were preliminarily polished zirconia ceramics glazed with Biomic and Stain/Glaze products, respectively; and untreated zirconia ceramics glazed with Biomic and Stain/Glaze products, respectively. The above 8 subgroups of zirconia ceramic specimens were used as friction pairs with 80 steatite ceramics for 50 000 chewing cycles under 50 N vertical load and artificial saliva lubrication using chewing simulation. Scanning electron microscope was used to observe the microstructure of the surface and section of the coating group, and the thickness of the coating and glazing were measured. The linear roughness of the coating and polishing groups was mea-sured using a laser confocal scanning microscope. Vickers hardness was measured using a microhardness tester and the esthetic of zirconia ceramic full crown sprayed with silicon-lithium coating was preliminarily evaluated. White light interferometer was used to measure the width, the maximum depth and the volume of the wear scars of each group, and the wear depth of steatite ceramics and wear rate of zirconia ceramic specimens were calculated. Kruskal-Wallis nonparametric test and Dunn's multiple comparisons test were used to analyze the wear depth of each group (α=0.05).@*RESULTS@#The microstructures of the silica-lithium spray coatings on the untreated and preliminarily polished zirconia ceramic surfaces showed the protruding defects, and the line roughness of coating group was larger than that of the polishing group. The median thickness of the silica-lithium spray coating on the preliminarily polished zirconia ceramic was 13.0 μm (interquartile range, IQR: 11.6, 17.9), while that of the silica-lithium spray coating on the untreated zirconia ceramic was 4.4 μm (IQR: 4.1, 4.7). The Vickers hardness and wear rate of the coating group were between the polishing group and the glazing group. The wear depths of the wear scars of steatite ceramics were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference between glazing and polishing groups (P < 0.05). With the increase of polishing procedure, the wear depth of steatite ceramics decreased in each subgroups. The orders of maximum depth and volume of wear scars of zirconia ceramic were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference in the maximum depth of wear scars between glazing and polishing groups (P < 0.05).@*CONCLUSION@#The silica-lithium spray coating on the zirconia ceramic, can be used as a new method for zirconia ceramic surface treatment, because it can increase the esthetic of zirconia ceramics compared with polishing and reduce the wear of steatite ceramics compared with glazing.

Analysis of dust monitoring results of dust exposure enterprises in Shenxian from 2017 to 2020 / 中华劳动卫生职业病杂志

Objective: In order to understand the dust concentration in the workplace of dust exposure enterprises in Shenxian. To evaluate the degree of occupational hazard factors of dust exposure enterprises. And provide basis for the formulation of occupational protection standards and management system of dust exposure enterprises. Methods: In February 2022, the dust concentration monitoring data of 89 dust exposure enterprises from 2017 to 2020 by the Shenxian Center for Disease Control and Prevention were collected, and the qualified rates of dust concentration detection of dust exposure enterprises in different years, dust types and enterprise sizes were analyzed. Results: A total of 89 dust enterprises were monitored from 2017 to 2020, 2132 dust samples were collected, and 1818 qualified samples were taken, with a total qualified rate of 85.3%. From 2017 to 2020, the dust detection qualified rates showed a year-by-year increase trend, 78.7% (447/568), 84.1% (471/560), 88.6% (418/472) and 90.6% (482/532), respectively, with statistically significant differences (χ(2)=36.27, P=0.003). The differences in the qualified rates of dust detection samples of silicon dust (66.1%, 41/62), grain dust (86.7%, 1549/1786), cotton dust (84.1%, 106/126) and wood dust (77.2%, 122/158) were statistically significant (χ(2)=29.66, P=0.002). The qualified rate of dust samples in large and medium-sized enterprises (95.1%, 1194/1256) was higher than that of small-sized enterprises (71.2%, 624/876), and the difference was statistically significant (χ(2)=1584.40, P=0.001) . Conclusion: The qualified rate of dust concentration monitoring results of dust exposure enterprises in Shenxian showed an increase trend year by year, while the pualified rate of dust concentration monitoring in small-sized enterprises was low, and the occupational hazard of silica dust was still severe.

Silicon as resistance inducer to control black apphid Aphis craccivora Koch, 1854 in cowpea beans [Vigna unguiculata (L)] Walp

The black aphid Aphis craccivora (Koch, 1854) stands out between the bugs considered cowpea pests. The objective of this study was to evaluate the effects of silicon application on the resistance induction of cowpea plants to the black aphid A. craccivora. The experiment was conducted in the Entomology Laboratory of the Phytosanitary sector of the Centro de Ciências Agrárias at the Universidade Federal do Piauí. The effects of the application of silicon on biological aspects were evaluated using a completely randomized design, with four treatments and 40 repetitions, being: silicon in soil (T1), silicon in soil + leaf (T2), silicone leaf (T3), and control (T4). The following biological variables were evaluated: generation period, reproductive period, fecundity, and daily average of nymphs per female. The silicon and lignin contents were also evaluated in the plants. The silicic acid was applied in a 1% solution around the stem of the plants (soil), 15 days after emergence, by diluting 2 g of the product in 200 mL of water. However, the leaf application was carried out with sprayer five days after application in soil. The non-preference of A. craccivora on bean was also evaluated. The evaluations were performed after 24, 48 and 72 hours of infestation by counting nymphs at 24, 48 and 72 hours and adults at each leaf session. The application of silicon promotes the reduction of the production of nymphs, interfering in the biological aspects of A. craccivora, and has potential to be used in a cowpea pest management program in cowpea.

Safe duration of silicon catheter replacement in urological patients

Objectives: This study compared the infection rates, degree of encrustation, symptoms, and complications in patients regarding the duration of urethral catheterisation (three weeks, six weeks, and eight weeks). Design: A cross-sectional study with stratified simple random sampling Setting: Urology Unit, Korle Bu Teaching Hospital Participants: One hundred and thirty-seven male patients with long-term urinary catheters Interventions: Participants were grouped into 3 weeks, 6 weeks, and 8 weeks duration of catheter replacementsPrimary outcomes measures: Symptoms due to the urinary catheters, urinalysis, urine and catheter tip cultures, sensitivity, and catheter encrustations were assessed. Results: Eighty-six patients had a primary diagnosis of benign prostatic hyperplasia (BPH), 35 had urethral strictures,13 had prostate cancer, two had BPH and urethral strictures, and one participant had bladder cancer. There was no difference in the symptoms the participants in the different groups experienced due to the urinary catheters (p > 0.05). The frequency of occurrence of complications (pyuria, p = 0.784; blocked catheter, p=0.097; urethral bleeding, p=0.148; epididymo-orchitis, p=0.769 and bladder spasms, p=1.000) showed no differences in the three groups. There was no statistical difference in the urinalysis for the three groups (p>0.05) and the degree of encrustations (3 weeks: 0.03 ± 0.06, 6 weeks: 0.11±0.27 and eight weeks: 0.12 ±0.27) with p=0.065. Conclusions: In this study, the duration of urinary catheterisation using silicone Foley's catheters did not influence the complication and symptom rates; hence silicon catheters can be placed in situ for up to 8 weeks before replacement instead of the traditional three-weekly change.

Water quality in the Lachuá Ecoregion Landscape: Comparing streams from Forest, Milpa, and an Oil Palm plantation / Calidad del agua en el paisaje de la Ecorregión Lachuá: Comparando arroyos en bosques, milpa y palma africana

The hydrological network in the Lachuá Ecoregion (EL), Alta Verapaz, Guatemala, hosts high levels of biodiversity and supplies water to 44 Mayan communities. Despite this critical fact, this network has been threatened by scarcely monitored industrial activities including the rapidly expanding oil palm monoculture (Elaeis guineensisJacq). Regardless of Lachua's freshwaters importance, there is little information on how this monoculture impacts them. We compared water-quality properties from streams in oil palm plantations (P), paddock and milpa systems (M), and primary forests (F) in the EL. During 2015-2016, 13 rivers were sampled (5 times) for water temperature, pH, dissolved oxygen (DO), conductivity, hardness, chemical and biochemical oxygen demand (COD and BOD), and concentration of silica, nitrates, phosphates, and ammonia. Several parameters showed significant differences. P were 2.7 ºC and 1.8 ºC warmer than M and F and carried 1.4 mg/L more nitrates than F. F carried 10.8 mg/L and 11.8 mg/L more silica than M and P. M showed intermediate temperatures and silica concentrations, as well as 14.8 µS/cm and 8.9 µS/cm lower conductivities than P and F, respectively. Additionally, COD in M was 9.9 mg/L and 4.6 mg/L lower than P and F, respectively. We believe higher temperatures and lower silica in P are due to the loss of riparian forest and their role in buffering temperatures and recycling silicon. In addition, the existence of secondary forest (guamil) in M might explain the intermediate temperatures and silica concentrations. Our results highlight the contributions of forests to waterways and suggest potential water-quality depletion from the oil palm expansion in the EL.

La red hídrica en la Ecorregión Lachuá (EL), Alta Verapaz, Guatemala, alberga una alta biodiversidad y abastece de agua a 44 comunidades mayas. Sin embargo, recientemente se ha visto amenazada por actividades industriales escasamente monitoreadas, incluido el creciente monocultivo de palma africana (Elaeis guineensis Jacq) del cual se desconocen sus impactos en la EL. Este estudio explora la calidad del agua de arroyos en plantaciones de palma africana (P), bosques primarios (B), y sistemas de potrero y milpa (M) en Lachuá. Durante 2015-2016, se tomaron muestras de 13 ríos (5 veces) para medir la temperatura del agua, pH, oxígeno disuelto (OD), conductividad, dureza, demanda química y bioquímica de oxígeno (DQO y DBO) y la concentración de sílice, nitratos, fosfatos, y amoníaco. Varios parámetros mostraron diferencias significativas. P fue 2.7 ºC y 1.8 ºC más calientes que M y F y portó 1.4 mg/L más nitrato que F. F portó 10.8 mg/L y 11.8 mg/L más sílice que M y P. M mostró temperaturas y concentraciones de sílice intermedias y conductividades 14.8 µS/cm y 8.9 µS/cm menores que P y F. La DQO en M fue 9.9 mg/L y 4.6 mg/L menor que P y F. El aumento de temperatura y la disminución de sílice en P podría deberse a la pérdida de bosques ribereños los cuales amortiguan la tempe-ratura y reciclan el silicio. La presencia de bosque secundarios (guamil) en M podría explicar las temperaturas y las concentraciones de sílice intermedias resaltando la importancia de los bosques en la red hídrica. Se predice un posible deterioro en el agua resultado de la expansión de palma africana en la EL.

Silicon as an attenuator of drought stress in plants of Oryza sativa L. treated with dietholate / Silício como atenuador de estresse hídrico em plantas de Oryza sativa L. tratadas com dietholate

Abstract Silicon (Si) is an element that can improve the growth and development of rice plants in water-deficient environments because it is an enzymatic stimulant, signaling for production of antioxidant compounds. Therefore, the aim of this study was to examine the relationship between water deficiency and the effect of Si on two rice cultivars whose seeds were treated with dietholate. The experimental design was fully randomized with three replicates, and treatments were organized in a 3x2x2x4 factorial arrangement: three water soil conditions (50% and 100% of soil water retention capacity (WRC) and complete submergence in a water blade of 5.0 cm); two cultivars (IRGA 424 RI and Guri INTA CL); two sources of Si (sodium metasilicate and potassium metasilicate); and four rates of Si (0; 4.0; 8.0 and 16 g L-1). Chlorophyll a and b, leaf area and shoot and root dry weight increased at higher rates of Si under the three soil water regimes. There was an increase in superoxide dismutase and guaiacol peroxidase enzyme activity in the cultivars at higher rates of Si, reducing lipid peroxidation caused by water deficiency. Therefore, Si did indeed attenuate water deficiency stress in rice plants emerging from seeds treated with dietholate.

Resumo O silício (Si) é um elemento que pode proporcionar melhor crescimento e desenvolvimento às plantas de arroz cultivadas em ambientes com deficiência hídrica, por ser um estimulador enzimático, promovendo sinalização para produção de compostos antioxidantes. Assim, o objetivo deste trabalho foi estudar a relação entre deficiência hídrica e o efeito do Si em duas cultivares de arroz tratadas com dietholate. O delineamento experimental utilizado foi inteiramente casualizado, com três repetições e os tratamentos arranjados em esquema fatorial 3x2x2x4, sendo os fatores: três condições hídricas do solo (50%, 100% da capacidade de retenção de água no solo (CRA) e lâmina d'água de 5,0 cm), duas cultivares (IRGA 424 RI e Guri INTA CL), duas fontes de Si (metassilicato de sódio e metassilicato de potássio) e quatro doses de Si (0; 4,0; 8,0 e 16 g L-1). O índice de clorofila a e b, a área foliar e o teor de massa seca da parte aérea e raiz aumentaram com o aumento das doses de Si nas três condições hídricas do solo. Houve um aumento na atividade das enzimas superóxido dismutase e guaiacol peroxidase nas cultivares estudadas à medida que as doses de Si aumentaram, diminuindo a peroxidação de lipídios, causada pela restrição hídrica. Portanto, o Si atenua o estresse por déficit hídrico em plantas de arroz emergentes de sementes tratadas com dietholate.

Functional relationship between photosynthetic leaf gas exchange in response to silicon application and water stress mitigation in sugarcane

BACKGROUND: Water stress is one of the serious abiotic stresses that negatively influences the growth, development and production of sugarcane in arid and semi-arid regions. However, silicon (Si) has been applied as an alleviation strategy subjected to environmental stresses. METHODS: In this experiment, Si was applied as soil irrigation in sugarcane plants to understand the mitigation effect of Si against harmful impact of water stress on photosynthetic leaf gas exchange. RESULTS: In the present study we primarily revealed the consequences of low soil moisture content, which affect overall plant performance of sugarcane significantly. Silicon application reduced the adverse effects of water stress by improving the net photosynthetic assimilation rate (Anet) 1.35-18.75%, stomatal conductance to water vapour (gs) 3.26-21.57% and rate of transpiration (E) 1.16-17.83%. The mathematical models developed from the proposed hypothesis explained the functional relationships between photosynthetic responses of Si application and water stress mitigation. CONCLUSIONS: Silicon application showed high ameliorative effects on photosynthetic responses of sugarcane to water stress and could be used for mitigating environmental stresses in other crops, too, in future.

Exploration of silicon functions to integrate with biotic stress tolerance and crop improvement

In the era of climate change, due to increased incidences of a wide range of various environmental stresses, especially biotic and abiotic stresses around the globe, the performance of plants can be affected by these stresses. After oxygen, silicon (Si) is the second most abundant element in the earth's crust. It is not considered as an important element, but can be thought of as a multi-beneficial quasi-essential element for plants. This review on silicon presents an overview of the versatile role of this element in a variety of plants. Plants absorb silicon through roots from the rhizospheric soil in the form of silicic or monosilicic acid. Silicon plays a key metabolic function in living organisms due to its relative abundance in the atmosphere. Plants with higher content of silicon in shoot or root are very few prone to attack by pests, and exhibit increased stress resistance. However, the more remarkable impact of silicon is the decrease in the number of seed intensities/soil-borne and foliar diseases of major plant varieties that are infected by biotrophic, hemi-biotrophic and necrotrophic pathogens. The amelioration in disease symptoms are due to the effect of silicon on a some factors involved in providing host resistance namely, duration of incubation, size, shape and number of lesions. The formation of a mechanical barrier beneath the cuticle and in the cell walls by the polymerization of silicon was first proposed as to how this element decreases plant disease severity. The current understanding of how this element enhances resistance in plants subjected to biotic stress, the exact functions and mechanisms by which it modulates plant biology by potentiating the host defence mechanism needs to be studied using genomics, metabolomics and proteomics. The role of silicon in helping the plants in adaption to biotic stress has been discussed which will help to plan in a systematic way the development of more sustainable agriculture for food security and safety in the future.

Silicon Mediated Alleviation of Salinity Stress Regulated by Silicon Transporter Genes (Lsi1 and Lsi2) in Indica Rice

Abstract Silicon accumulation is known to improve tolerance of plants under both biotic and abiotic stress. Salinity stress is an inevitable crisis causing wide spread damage to rice leading to food insecurity. The influence of Si (1mM) on two rice cultivars cv. Ghanteswari (high accumulator) and cv.Badami (low accumulator) which differs in Si uptake potential under saline (10ds/m EC) and non- saline conditions were studied in nutrient culture. The Si transporter genes were isolated and characterized to determine their function in salinity tolerance. Under stress, there was an increase in Si accumulation, Na+/K+ ratio, electrolyte leakage, lipid peroxidation and antioxidant activities. On addition of silicon, the K+ uptake increased, membrane damage reduced and osmolytes balance improve under salinity. But, the level of resurgence was varied in both cultivars, due to their differential Si-accumulation. Molecular characterizations of Lsi1 protein revealed its involvement in the movement of ion and water and therefore prevent osmotic stress. The Lsi2 is responsible for removal of Na+, reducing salt toxicity. Silicon accumulation is responsible for maintenance of cell water status, osmotic balance and Na+ ion exclusion during high salinity. The variable relative expression of Lsi2 provides a possible explanation for differential genotypic uptake of silicon.

Retinal Toxicity Following the Injection Ganciclovir into Silicone Oil-filled Eye to Treat Acute Retinal Necrosis

PURPOSE: To report a case of retinal toxicity after an intravitreal ganciclovir injection to treat acute retinal necrosis in an eye filled with silicone oil.CASE SUMMARY: A 56-year-old male presented with ocular pain and visual loss in his right eye. His best-corrected visual acuity was 20/25, inflammatory cells in the anterior chamber, multiple retinitis lesions and retinal vessel occlusions in the peripheral retina and vitreous opacity were showed. Acute retinal necrosis was suspected, anterior chamber polymerase chain reaction (PCR) test was done. Aciclovir 2,400 mg/day intravenously and ganciclovir 2.0 mg were administered by intravitreal injection. After 4 days, retinitis was worsened and PCR test was positive for varicella zoster virus. Ganciclovir intravitreal injections were increased twice a week. After 16 days, retinal detachment occurred, so scleral encircling, vitrectomy, laser photocoagulation, and silicone oil tamponade were conducted. Ganciclovir 1.0 mg was injected at the end of surgery. The patient's visual acuity decreased to hand motion, and multiple crystal deposits with multiple retinal hemorrhages were observed in the right eye the next day. Visual acuity did not recover and optical coherent tomography showed that the macula was thinned.CONCLUSIONS: Visual loss seemed to be related with the retinal toxicity of ganciclovir. The increased local concentration due to the silicone oil tamponade is thought to have caused the toxicity.

Portable model for vasectomy reversal training

ABSTRACT Objectives To validate an experimental non-animal model for training of vasectomy reversal. Materials and Methods The model consisted of two artificial vas deferens, made with silicon tubes, covered by a white resin, measuring 10 cm (length) and internal and external diameters of 0.5 and 1.5 mm, respectively. The holder of the ducts is made by a small box developed with polylactic acid, using a 3D print. The objective of the invention is to simulate the surgical field of vasovasostomy, when the vas deferens are isolated from other cord structures. For validation, it was verified the acquisition of microsurgical skills during its use, in a capacitation course with 5 urology residents from a Hospital of the region. Along the training sessions, it was analyzed the time (speed) of microsurgical sutures, and quantification of the performance using a checklist. Collected data were analyzed using de BioEstat®5.4 software. Results Medium time for the completion of microsurgical sutures improved considerably during the course, and reached a plateau after the third day of training (p=0.0365). In relation to the checklist, it was verified that during capacitation, there was significant improvement of the scores of each participant, that reached a plateau after the fourth day of training with the model (p=0.0035). Conclusion The developed model was able to allow the students that attended the course to gain skills in microsurgery, being considered appropriate for training vasectomy reversal.

Tolerance to hydric stress on cultivars of silicon-fertilized corn crops: absorption and water-use efficiency / Tolerância ao estresse hídrico em cultivares de milho adubadas com silício: absorção e eficência no uso da água

Silicon (Si) plays specific functions in agriculture. Si is a beneficial element, as it accumulates at high amounts in plant tissue. Si accumulation in cell walls reduces water loss by transpiration and may be an adaptation factor to water stress. This study evaluated the efficiency of different corn crops using calcium silicate as a reducer of hydric stress. The experiment was organized in a factorial scheme, completely randomized, with two doses of calcium silicate (0 and 100 % according to soil liming) with two irrigation depths: (30 and 100 % of necessary water reposition in the soil) and two corn cultivars: (cv. BRS-1010) considered sensitive to hydric stress and (cv. DKB-390) tolerant to hydric stress. The study comprised four repetitions. We studied dry matter production on leaves and stem, weight of 1000 seeds and crop yield. We measured efficiency of gas exchange and water use to compare the different treatments. The results for stem and leaves dry matter were better in both cultivars when using calcium silicate, regardless of irrigation depth. Both corn cultivars cv. BRS-1010, sensitive to hydric stress, and cv. DKB-390, tolerant to hydric stress, had greater yield in the presence of calcium silicate, when at the smallest irrigation dose was applied. The treatment with calcium silicate was the most efficient in water use, using 30% of irrigation depth. Cv. DKB 390 was the most productive, with greater tolerance to water stress.

O silício (Si) desempenha funções específicas na agricultura, sendo considerado um elemento benéfico, pois se acumula em quantidades elevadas no tecido da planta. O acúmulo de Si nas paredes celulares reduz a perda de água pela transpiração e pode ser um fator de adaptação ao estresse hídrico. Este estudo avaliou a eficiência de diferentes cultivares de milho utilizando o silicato de cálcio como amenizador do estresse hídrico. O experimento foi organizado em esquema fatorial, inteiramente casualizado, com duas doses de silicato de cálcio (0 e 100% de acordo com a calagem do solo), com duas lâminas de irrigação (30 e 100% de reposição de água necessária no solo) e duas cultivares de milho: a (cv. BRS-1010) considerada sensível ao estresse hídrico e a (cv. DKB-390) tolerante ao estresse hídrico, com quatro repetições. Estudamos a produção de matéria seca em folhas e caule, o peso de 1000 sementes e o rendimento da cultura. Medimos a eficiência das trocas gasosas e do uso da água para comparar os diferentes tratamentos. Os resultados para matéria seca do caule e das folhas foram melhores em ambas as cultivares, quando utilizadas o silicato de cálcio, independente da lâmina de irrigação. As duas cultivares de milho estudadas, cv. BRS-1010 tolerante ao estresse hídrico e o DKB-390 tolerante ao estresse hídrico apresentaram maior produção na presença de silicato de cálcio, quando a menor lâmina de água foi aplicada. A maior eficiência no uso da água foi obtida no tratamento com silicato de cálcio, utilizando 30% de irrigação. A cv. DKB 390 foi a mais produtiva, com maior tolerância ao déficit hídrico.

Silicon as resistance inducer in to control black aphid Aphis craccivora Koch, 1854 in Phaseolus lunatus lima beans / Silício como indutor de resistência no controle do pulgão preto Aphis craccivora Koch, 1854 em fava Phaseolus lunatus

In Brazil, there are few records of insects associated with the cultivation of lima beans; among them, there is the black aphid Aphis craccivora Koch, 1854. The objective of this study was to evaluate the effects of silicon application on the resistance induction of lima bean plants, Phaseolus lunatus, to the black aphid A. craccivora. The experiment was conducted in the Entomology Laboratory of the Phytosanitary Sector of Centro de Ciências Agrárias, Universidade Federal do Piauí (UFPI), Brazil. The effects of the following treatments on biological aspects of the insect were evaluated: silicon applied to soil; silicon applied to soil + leaf; silicon applied to leaf; and control, without silicon application. The following biological variables were evaluated: generation period, reproductive period, and the fertility and daily average of produced nymphs per female. Plant silicon and lignin content were also evaluated. A 1% solution of silicic acid (2.0 g of product diluted in 200 mL of water) was applied around the plant stem (on soil), 15 days after emergence. Leaf application was performed with a 1-L spray, 5 days after the soil application. The non-preference of A. craccivora on lima beans was also evaluated. The evaluations were performed after 48 and 72 hours of infestation by counting nymphs and adults at each leaf section. Silicon application reduces nymph production, thereby interfering in the biological aspects of A. craccivora. Therefore, it can be used in cowpea pest management programs.(AU)

São poucos os registros no Brasil de insetos associados à cultura da fava; entre eles, destaca-se o pulgão preto Aphis craccivora Koch, 1854. O objetivo deste estudo foi avaliar os efeitos da aplicação de silício na indução de resistência de plantas de feijão-fava Phaseolus lunatus a esse inseto. O experimento foi conduzido no Laboratório de Entomologia do setor de Fitossanidade do Centro de Ciências Agrárias da Universidade Federal do Piauí (UFPI). Os efeitos da aplicação do silício sobre os aspectos biológicos do inseto foram avaliados utilizando os tratamentos: silício aplicado no solo, silício aplicado no solo + folha, silício aplicado à folha; e controle, sem aplicação de silício. Foram avaliadas as variáveis biológicas: duração do período pré-reprodutivo, período reprodutivo e fertilidade, e média diárias de ninfas produzidas por fêmea. Os teores de silício e de lignina nas plantas também foram avaliados. O ácido silícico foi aplicado em uma solução a 1% ao redor do caule das plantas (no solo), 15 dias após a emergência, diluindo-se 2,0 g do produto em 200 mL de água. Já a aplicação foliar foi realizada com um pulverizador de 1 L, 5 dias após a aplicação em solo. A não preferência de A. craccivora em feijão também foi avaliada. As avaliações foram realizadas após 48 e 72 horas da infestação, por meio da contagem de ninfas e adultos em cada secção foliar. A aplicação de silício promove a redução da produção de ninfas, interferindo nos aspectos biológicos de A. craccivora, podendo ser utilizado em programas de manejo de pragas do feijão-fava.(AU)

Carbon-Fiber Based Microelectrode Array Embedded with a Biodegradable Silk Support for In Vivo Neural Recording

BACKGROUND: Recently, carbon fibers have been utilized to develop a depth-type microelectrode array for chronic neural recording. Since the diameter of carbon fibers is smaller than the conventional electrodes made of metal wires or microfabricated silicon, the carbon fiber electrodes showed an improved capability for chronic neural recording with less tissue damages. However, the carbon fiber based microelectrodes have a limitation of short insertion depth due to a low stiffness. METHODS: We proposed a carbon fiber based microelectrode array embedded with a mechanical support structure to facilitate the penetration into the deeper brain. The support is made of biodegradable silk fibroin to reduce the reactive tissue responses. The 4-channel carbon fiber based microelectrode arrays were fabricated and accessed in terms of electrochemical impedance, recording capability for 1-month implantation in rat hippocampi. The electrodes with tungsten supports were fabricated and tested as a control group. Immunohistochemical analysis was performed to identify the reactive glial responses. RESULTS: The carbon fiber based electrode arrays with silk supports showed about 2-fold impedance increase 2 weeks after implantation while the number of active electrodes decreased simultaneously. However, after 1 month, the electrode impedance decreased back to its initial value and the percentage of active electrodes also increased above 70%. Immunohistochemical staining clearly showed that the electrodes with silk supports induced less reactive glial responses than that with tungsten supports. CONCLUSION: The proposed carbon fiber based microelectrode array is expected to be used for long-term in vivo neural recording from deep brain regions with the minimized reactive tissue response.

Comparison of the diagnostic yield of various systematic randomized prostate biopsy protocols using prostate phantoms made of devil's tongue jelly

PURPOSE: The purpose of this study was to compare the diagnostic yield of five systematic randomized protocols using 12–20 biopsy cores with variably-sized phantoms. METHODS: A total of 100 prostate phantom models were produced by casting liquid devil's tongue jelly using silicone molds. Sets of 20 phantoms were created with the following volumes: 20 mL, 40 mL, 60 mL, 80 mL, and 100 mL. Three focal lesions were created by injecting 0.5 mL of warm agar solution stained with red, blue, and green ink into each phantom model. The focal lesions were verified by ultrasonography. The systematic randomized biopsy protocols consisted of 12, 14, 16, 18, and 20 biopsy cores. The diagnostic yield of the multiple systematic biopsy protocols was compared. RESULTS: The overall detection rates of each model set were 93.3% for 20 mL, 88.3% for 40 mL, 71.7% for 60 mL, 43.3% for 80 mL, and 30.0% for 100 mL. Statistically significant differences in the detection rate were found between 40 mL and 60 mL and between 60 mL and 80 mL. No statistically significant increase in the detection rate was observed within a given volume set even when the number of core biopsies increased from 12 to 20. CONCLUSION: The diagnostic yield of systematic randomized biopsies is inversely proportional to the phantom volume.

Deposição de hidreto de silício sobre a zircônia em diferentes tempos: análise química, microestrutural e durabilidade da união ao cimento resinoso / Deposition of silicon hydride on the zirconia in different times: chemical, microstructural analyses and bond strenght with resin cement

O objetivo deste estudo foi avaliar a Deposição Química na Fase Vapor Assistido por Plasma (PECVD) com hidreto de silício (SiH4) em zircônia VITA YZ HT em diferentes tempos, bem como os seus efeitos nas características superficiais do material e na união ao cimento resinoso antes e após a termociclagem. Blocos de zircônia Vita YZ HT foram obtidos, polidos, sinterizados e divididos em 5 grupos, de acordo com o tempo de PECVD (n = 31): Zr-30 (30s), Zr-60 (60s), Zr-120 (120s) e Zr-300 (300s). O grupo controle (Zr-0) não recebeu deposição. Análises de DRX, FTIR, EDS, FE-SEM, XPS, goniometria e perfilometria foram utilizadas para caracterização química e topográfica. O silano Monobond N foi aplicado na superfície e um cilindro de cimento resinoso (Variolink N) foi confeccionado (3 × 3 mm). Metade dos espécimes de cada grupo foi armazenada por 24 h ou submetida à termociclagem (6 × 10³ ciclos). Teste de resistência ao cisalhamento (SBS) foi realizado. Os resultados foram submetidos aos testes one-way Anova e Tukey (α = 0,05). Para os grupos experimentais, o XPS mostrou que a formação de ligações Si-O contribuiu para o aumento da Energia Livre de Superfície (ELS). MEV-FEG e EDS mostraram que quanto maior o tempo de deposição, maior a quantidade de silício na superfície, apresentando apenas fase tetragonal. Zr-60 e Zr-300 apresentaram maior e menor rugosidade superficial, respectivamente. O silício penetrou na microestrutura, causando maior concentração de tensão. A resistência de união ao cimento resinoso foi melhorada após todos os tempos de deposição da PECVD. Portanto, a técnica de PECVD com o composto químico SiH4 associada ao tratamento químico com primer universal baseado em metacrilato de silano é uma alternativa promissora para a manutenção da ligação entre cimento resinoso e zircônia HT(AU)

The aim of this study was to evaluate the effect of Plasma-enhanced Chemical Vapor Deposition (PECVD) with silicon hydride (SiH4) on VITA YZ HT zirconia at different times, as well as its effects on material surface characteristics and bonding to resin cement before and after thermocycling. Blocks of VITA YZ HT zirconia were obtained, polished, sintered, and divided into five groups, according to PECVD time (n = 31): Zr-30 (30 s), Zr-60 (60 s), Zr-120 (120 s), and Zr-300 (300 s). The control group (Zr-0) did not receive deposition. XRD, FTIR, EDS, FE-SEM, XPS, goniometry, and profilometry analyses were used for chemical and topographic characterization. Monobond N silane was applied to the surface, and a cylinder of resin cement (Variolink N) was made (3 × 3 mm). Half of the specimens of each group were stored for 24 h or subjected to thermocycling (6 × 10³ cycles). A shear bond strength (SBS) test was performed. Results were subjected to one-way ANOVA and Tukey's tests (α = 0.05). For experimental groups, XPS showed that formation of Si-O bonds contributed to increased Surface Free Energy (SFE). FE-SEM and EDS showed that the longer the deposition time, the greater the amount of silicon on the surface, presenting only a tetragonal phase. Zr-60 and Zr-300 presented higher and lower surface roughnesses, respectively. The silicon penetrated the microstructure, causing higher stress concentrations. The bond strength to resin cement was improved after all PECVD deposition times. Thus, the PECVD technique with the chemical compound SiH4, associated with chemical treatment with universal primer based on silane methacrylate, is a promising alternative for maintaining bonding between resin cement and HT zirconia(AU)

An Unusual Case of Double Lacrimal Puncta

PURPOSE: Congenital double puncta are usually unilateral, and the accessory punctum exists on the medial side in a slit configuration that is distinct from the shape of the normal punctum. We report a case of an unusual case of double lacrimal puncta which the lateral, rather than the medial, punctum was judged to be the accessory punctum. CASE SUMMARY: A 39-year-old male patient with no underlying disease and no ophthalmologic history visited our clinic with right eye epiphora of 2 weeks duration. On slit lamp examination, double puncta were observed in the right lower eyelid and the remaining puncta were normal. On lacrimal syringing test and dacryocystography were performed and revealed incomplete obstruction with partial narrowing of the nasolacrimal duct. Silicone tube intubation was performed through the right lower medial punctum and symptoms improved postoperatively. CONCLUSIONS: The present case is an unusual case of double lacrimal puncta which has not been reported in Korea. Unlike the previous literature, the lateral, rather than the medial, punctum was judged to be the accessory punctum. Because accessory punctm can be present on the lateral side, it is necessary to distinguish between the accessory punctm and the main punctum through the accurate dacryocystography and lacrimal syringing test for the treatment of the patient.

Clinical Outcomes of Nasolacrimal Probing and Silicone Intubation in Patients with Congenital Nasolacrimal Duct Obstruction

PURPOSE: To investigate the efficacy and factors affecting the success rates of nasolacrimal probing and silicone intubation (SI) in patients with congenital nasolacrimal duct obstruction (CNLDO). METHODS: We retrospectively reviewed the medical records of patients including 69 eyes of 59 patients who received probing and 61 eyes of 49 patients who received SI. In patients with probing, the age, sex, and history of conservative treatment were analyzed in the success and failure groups, and a success rate comparison was conducted by dividing these values into postnatal group 1 ( 12 months, the success rate of probing was lower than in patients 12 months.

Utilizing a Previous Silicone Band Track in Recurred Retinal Detachment

PURPOSE: We report a case of utilizing a previous silicone band track in the reoperation of scleral encircling. CASE SUMMARY: An 8-year-old male presented with rhegmatogenous retinal detachment in the right eye. Five days after this diagnosis, he received scleral buckling surgery and cryopexy to seal the retinal tear. One month after surgery, a fundus examination showed subretinal fluid at the inferior site of the scleral buckle. He underwent scleral encircling surgery and a cryopexy procedure. The patient has had an uneventful postoperative course, and the retina has remained attached over a follow-up period of 9 months. However, exotropia and hypotropia developed in the right eye. Diagnosis of restrictive strabismus due to tissue adhesion around the silicone band was made. The encircling band was therefore removed and laser photocoagulation was performed 360° around the retina. Twenty-four hours after surgery, a fundus examination showed subretinal fluid. He received 360° scleral encircling surgery not using the 360° conjunctival peritomy. After confirming a previous encircling tract using #0-0 polydioxanone as a guide, #5-0 Nylon was tied to the end of the guide and inserted through the encircling tract with the end sutured with the silicone band. The silicone band was inserted into the encircling tract by pulling the #5-0 Nylon as a guide. Ophthalmoscopy revealed an attached retina with indentation of the scleral buckle at 360°. CONCLUSIONS: For reoperation in patients who previously underwent scleral encircling surgery, using the previous scleral encircling tract may be effective in cases with conjunctival and tissue adhesion.