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1.
Pharmacol Res ; 184: 106412, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36007774

RESUMEN

BACKGROUND: Viral- and host-targeted traditional Chinese medicine (TCM) formulae NRICM101 and NRICM102 were administered to hospitalized patients with COVID-19 during the mid-2021 outbreak in Taiwan. We report the outcomes by measuring the risks of intubation or admission to intensive care unit (ICU) for patients requiring no oxygen support, and death for those requiring oxygen therapy. METHODS: This multicenter retrospective study retrieved data of 840 patients admitted to 9 hospitals between May 1 and July 26, 2021. After propensity score matching, 302 patients (151 received NRICM101 and 151 did not) and 246 patients (123 received NRICM102 and 123 did not) were included in the analysis to assess relative risks. RESULTS: During the 30-day observation period, no endpoint occurred in the patients receiving NRICM101 plus usual care while 14 (9.27%) in the group receiving only usual care were intubated or admitted to ICU. The numbers of deceased patients were 7 (5.69%) in the group receiving NRICM102 plus usual care and 27 (21.95%) in the usual care group. No patients receiving NRICM101 transitioned to a more severe status; NRICM102 users were 74.07% less likely to die than non-users (relative risk= 25.93%, 95% confidence interval 11.73%-57.29%). CONCLUSION: NRICM101 and NRICM102 were significantly associated with a lower risk of intubation/ICU admission or death among patients with mild-to-severe COVID-19. This study provides real-world evidence of adopting broad-spectrum oral therapeutics and shortening the gap between outbreak and effective response. It offers a new vision in our preparation for future pandemics.


Asunto(s)
COVID-19 , COVID-19/terapia , Humanos , Medicina Tradicional China , Puntaje de Propensión , Estudios Retrospectivos , SARS-CoV-2
2.
Anim Biotechnol ; 33(5): 964-969, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33287639

RESUMEN

Genome-wide association studies (GWAS) have accelerated the identification of functional trait loci in cattle and identified single nucleotide polymorphisms (SNPs) in candidate genes associated with fertility and production traits in high milk yield dairy cattle. The fertility of Hanwoo (Korean native beef cattle) has declined after the adaptation of a selection program for high quantity and quality meat. However, there are few GWAS studies of fertility in beef cattle. We performed a genome-wide association study of 40 Korean native beef cattle heifers with imputed 770 K genotype and identified 12 significant SNPs within seven regions on three chromosomes (BTA 8, BTA 16 and BTA 24) associated with services per conception (SPC). Five SNPs were located in the ABCA1, BRINP3 and ESRRG genes, which are involved in early embryo development. In addition, 27 proximal genes were identified within 1 Mb of the candidate SNPs, which are involved in muscle cell differentiation and muscle structure development. However, we did not find any previously reported SNPs related to fertility in Holstein cows. Taken together, we identified SNPs associated with SPC and their proximal genes using gene-based analysis and the candidates were different from SNPs associated with subfertility of dairy cattle.


Asunto(s)
Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple , Animales , Bovinos/genética , Femenino , Fertilidad/genética , Estudio de Asociación del Genoma Completo/veterinaria , Genotipo , Polimorfismo de Nucleótido Simple/genética , República de Corea
3.
Anim Biotechnol ; 31(3): 189-194, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31060422

RESUMEN

The objective of this study was to investigate the association of DNA methylation with postmortem energy metabolism and the pH of the porcine longissimus dorsi muscle (LDM). Analysis of the DNA methylome of eight LDM samples (four pairs of the highest and lowest pH among littermates) identified a total of 3468 differentially methylated regions (DMRs) between high and low pH samples (p ≤ 0.001). Of DMRs, 45.3% co-mapped with quantitative trait loci known to be associated with meat pH and postmortem metabolism. Among the DMRs, 203 hyper-methylated regions (HR) and 190 hypo-methylated regions (HO) were identified for the high pH group compared to the low pH. Furthermore, 44 and 21 protein-coding genes contained HR and HO in their gene body, respectively. It was revealed that ENO1, GYS2, SDHC and DERA, which encode core enzymes in postmortem energy metabolism, contained HR or HO in their gene body.


Asunto(s)
Metilación de ADN/genética , Carne , Músculos Superficiales de la Espalda/química , Animales , ADN/análisis , ADN/química , ADN/genética , Femenino , Concentración de Iones de Hidrógeno , Carne/análisis , Carne/normas , Cambios Post Mortem , Sitios de Carácter Cuantitativo/genética , Porcinos
4.
Asian-Australas J Anim Sci ; 32(1): 92-102, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30056686

RESUMEN

OBJECTIVE: To investigate changes in rumen fermentation characteristics and bacterial community by a sudden change to a high concentrate diet (HC) in Korean domestic ruminants. METHODS: Major Korean domestic ruminants (each of four Hanwoo cows; 545.5±33.6 kg, Holstein cows; 516.3±42.7 kg, and Korean native goats; 19.1±1.4 kg) were used in this experiment. They were housed individually and were fed ad libitum with a same TMR (800 g/kg timothy hay and 200 g/kg concentrate mix) twice daily. After two-week feeding, only the concentrate mix was offered for one week in order to induce rapid rumen acidosis. The rumen fluid was collected from each animals twice (on week 2 and week 3) at 2 h after morning feeding using an oral stomach tube. Each collected rumen fluid was analyzed for pH, volatile fatty acid (VFA), and NH3-N. In addition, differences in microbial community among ruminant species and between normal and an acidosis condition were assessed using two culture-independent 16S polymerase chain reaction (PCR)-based techniques (terminal restriction fragment length polymorphism and quantitative real-time PCR). RESULTS: The HC decreased ruminal pH and altered relative concentrations of ruminal VFA (p<0.01). Total VFA concentration increased in Holstein cows only (p<0.01). Terminal restriction fragment length polymorphism and real-time quantitative PCR analysis using culture-independent 16S PCR-based techniques, revealed rumen bacterial diversity differed by species but not by HC (p<0.01); bacterial diversity was higher in Korean native goats than that in Holstein cows. HC changed the relative populations of rumen bacterial species. Specifically, the abundance of Fibrobacter succinogenes was decreased while Lactobacillus spp. and Megasphaera elsdenii were increased (p<0.01). CONCLUSION: The HC altered the relative populations, but not diversity, of the ruminal bacterial community, which differed by ruminant species.

5.
Asian-Australas J Anim Sci ; 32(11): 1705-1714, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31480139

RESUMEN

OBJECTIVE: Reducing roughage feeding without negatively affecting rumen health is of interest in ruminant nutrition. We investigated the effects of roughage sources and concentrate types on growth performance, ruminal fermentation, and blood metabolite levels in growing cattle. METHODS: In this 24-week trial, 24 Hanwoo cattle (224±24.7 kg) were fed similar nitrous and energy levels of total mixed ration formulated using two kinds of roughage (timothy hay and ryegrass straw) and two types of concentrate mixes (high starch [HS] and high fiber [HF]). The treatments were arranged in a 2×2 factorial, consisting of 32% timothy-68% HS, 24% timothy-76% HF, 24% ryegrass-76% HS, and 17% ryegrass-83% HF. Daily feed intakes were measured. Every four weeks, blood were sampled, and body weight was measured before morning feeding. Every eight weeks, rumen fluid was collected using a stomach tube over five consecutive days. RESULTS: The mean dry matter intake (7.33 kg) and average daily gain (1,033 g) did not differ among treatments. However, significant interactions between roughage source and concentrate type were observed for the rumen and blood parameters (p<0.05). Total volatile fatty acid concentration was highest (p<0.05) in timothy-HF-fed calves. With ryegrass as the roughage source, decreasing the roughage inclusion rate increased the molar proportion of propionate and decreased the acetate-to-propionate ratio; the opposite was observed with timothy as the roughage source. Similarly, the effects of concentrate types on plasma total protein, alanine transaminase, Ca, inorganic P, total cholesterol, triglycerides, and creatinine concentrations differed with roughage source (p<0.05). CONCLUSION: Decreasing the dietary roughage inclusion rate by replacing forage neutral detergent fiber with that from non-roughage fiber source might be a feasible feeding practice in growing cattle. A combination of low-quality roughage with a high fiber concentrate might be economically beneficial.

6.
Dermatol Surg ; 44(11): 1411-1420, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29957664

RESUMEN

BACKGROUND: Previous studies have reported the benefits of low-level/light laser therapy (LLLT) for the promotion of hair regrowth. However, the effectiveness of LLLT for the treatment of androgenetic alopecia (AGA) is still a topic of debate. OBJECTIVE: To investigate the efficacy and safety of LLLT on hair regrowth in patients with AGA. METHODS: This 24-week, randomized, double-blind, self-comparison, sham device-controlled trial enrolled 100 patients with AGA. All participants were randomly assigned to receive the investigational LLLT on one side of the head and sham light treatment on the contralateral side, 3 times weekly for 30 minutes each, over a 24-week period. Global scalp photography, phototrichogram assessment, the investigator's global assessment (IGA) of hair regrowth, and the subject's assessment of the treatment satisfaction were used for evaluation. RESULTS: After 24 weeks of treatment, the LLLT-treated scalp exhibited significantly greater hair coverage than the sham light-treated side (14.2% vs. 11.8%, p < .001). A significantly greater improvement from baseline in hair thickness, hair count, hair coverage, and IGA were also observed in the LLLT-treated side than in the sham light-treated side at the 12- and 24-week visits. No serious adverse events were observed. CONCLUSION: The use of LLLT might be an effective, safe, well-tolerated treatment for AGA.


Asunto(s)
Alopecia/radioterapia , Terapia por Luz de Baja Intensidad/métodos , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Taiwán , Resultado del Tratamiento
7.
Hum Genomics ; 10(1): 40, 2016 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-28031051

RESUMEN

Jayson GC et al. remarked in Lancet that nearly 100% of mucinous ovarian cancer cases have Kras mutation as well as a high frequency of Her2 amplification. Using the Abbott PathVysion Her2 DNA Probe Kit and Kras mutant-enriched PCR Kits (FemtoPath®), 21 samples of primary ovarian mucinous cystadenocarcinomas from Taiwanese patients were examined to determine the status of Her2 amplification and Kras mutations. Our results showed the Her2 amplification rates were 33.33%, while the Kras mutation rates were 61.90%. We present here our results in order to enlighten the readership that the ~100% Kras mutant frequency and the high Her2 amplification rate reported by Jayson et al. may be too exaggerated to be applicable into all populations. Additionally, we report another 2 novel Kras mutations (A11V, V14I).


Asunto(s)
Adenocarcinoma Mucinoso , Carcinoma Epitelial de Ovario , Neoplasias Ováricas , Femenino , Humanos , Mutación , Proteínas Proto-Oncogénicas p21(ras)
11.
Stat Med ; 33(5): 772-85, 2014 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-24122926

RESUMEN

Multivariate current-status failure time data consist of several possibly related event times of interest, in which the status of each event is determined at a single examination time. If the examination time is intrinsically related to the event times, the examination is referred to as dependent censoring and needs to be taken into account. Such data often occur in clinical studies and animal carcinogenicity experiments. To accommodate for possible dependent censoring, this paper proposes a joint frailty model for event times and dependent censoring time. We develop a likelihood approach using Gaussian quadrature techniques for obtaining maximum likelihood estimates. We conduct extensive simulation studies for investigating finite-sample properties of the proposed method. We illustrate the proposed method with an analysis of patients with ankylosing spondylitis, where the examination time may be dependent on the event times of interest.


Asunto(s)
Funciones de Verosimilitud , Modelos Estadísticos , Análisis de Regresión , Simulación por Computador , Humanos , Inmunoglobulina A/sangre , Espondilitis Anquilosante/fisiopatología
12.
Anim Biosci ; 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38665083

RESUMEN

Objective: This study investigated the repeatability of feed efficiency and its association with carcass traits in Hanwoo steers during the entire growing and fattening periods. Methods: The growth and intake of thirty-six Hanwoo steers (259 ± 19.7 kg; nine months) were monitored throughout five periods, including two growing periods (GP) and three fattening periods (FP). The steers were fed two types of concentrate mixes with varying nutrient compositions until they reached a target weight of 800 kg for slaughter. For each period, steers were categorized into three classes based on their feed efficiency rankings using residual feed intake (RFI) and feed conversion ratio (FCR). Feed efficiency repeatability was assessed using the Spearman correlation coefficient, decomposition of random errors, and the Theil segregation index (TSI). The Pearson correlation coefficient was used to examine the relationship between feed efficiency and carcass traits. Results: The results demonstrated a significant and high correlation with RFI, but not FCR, during the growing or fattening stages (r > 0.5; P < 0.01). When steers were classified according to their feed efficiency rankings, 58% of the animals in the high RFI class (low efficient) initially (GP 1) remained in the same class by the last period (FP 3), whereas steers were randomly distributed based on FCR. The repeatability, assessed by the decomposition of random errors, was higher for RFI (0.61) than for FCR (0.15). The TSI also indicated that RFI rankings, rather than FCR rankings, are more likely to be maintained. Moreover, a weak association was observed between feed efficiency and carcass traits. Conclusion: In conclusion, RFI repeatability throughout the growing and fattening periods surpassed that of the FCR, with steers classified as high RFI during the GP more likely to remain in the same class during the FP. Feed efficiency was weakly correlated with carcass traits.

13.
Animals (Basel) ; 14(3)2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38338112

RESUMEN

This study aimed to investigate the effect of varying levels of dietary crude protein (CP) on growth performance, rumen characteristics, blood metabolites, and methane emissions in fattening Hanwoo steers. Twenty-four steers, weighing 504 ± 33.0 kg (16 months old), were assigned to four dietary treatments with different CP concentrations (15, 18, 19, and 21% of CP on a dry matter (DM) basis). A linear increasing trend in the average daily gain (ADG) was observed (p = 0.066). With increased dietary CP levels, the rumen ammonia concentration significantly increased (p < 0.001), while the propionate proportion linearly decreased (p = 0.004) and the proportions of butyrate and valerate linearly increased (p ≤ 0.003). The blood urea exhibited a linear increase (p < 0.001), whereas the blood non-esterified fatty acids and cholesterol showed a linear decrease (p ≤ 0.003) with increasing dietary CP. The methane concentration from eructation per intake (ppm/kg), forage neutral detergent fiber (NDF) intake, total NDF intake, and ADG exhibited linear decreases (p ≤ 0.014) across the treatments. In conclusion, increasing the dietary CP up to 21% in concentrates demonstrated a tendency to linearly increase the ADG and significantly decrease the propionate while increasing the butyrate. The methane concentration from eructation exhibited a tendency to linearly decrease with increasing dietary CP.

14.
Artículo en Inglés | MEDLINE | ID: mdl-38689071

RESUMEN

Recent clinical evidence shows that the antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) can successfully treat patients with advanced HER2-mutant non-small cell lung cancer (NSCLC). We aimed to characterize HER2 mutations in cervical neuroendocrine carcinoma (NEC) among Taiwanese women to provide the rationale for exploring T-DXd as a tumor-agnostic targeted therapy option. We analyzed 12 archived primary cervical NEC samples from Taiwanese patients. Tumor-rich areas were marked for microdissection on 10 µm unstained sections. DNA was extracted, and HER2 hotspots were sequenced using a targeted panel on the Illumina MiSeq. HER2 missense mutations were identified in 5 of 12 cases (41.7%). Of the 5 cases with mutations, 2 patients (40%) had a single mutation, while 3 patients (60%) had double mutations. We detected 4 substitutions outside the tyrosine kinase domain (non-TKD), which were p.P1170A, p.S305C, p.I655V, and a novel T328K alteration. No mutations were found within the tyrosine kinase domain (TKD). The 41.7% HER2 mutation rate warrants expanded screening and future clinical investigation of the T-DXd targeting HER2 mutations in cervical NEC patients. Overall, this study contributes to the molecular understanding of cervical NEC and lays the groundwork for developing more effective treatment strategies.

15.
Sci Rep ; 14(1): 8704, 2024 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622291

RESUMEN

Grasslands cover approximately 24% of the Earth's surface and are the main feed source for cattle and other ruminants. Sustainable and efficient grazing systems require regular monitoring of the quantity and nutritive value of pastures. This study demonstrates the potential of estimating pasture leaf forage mass (FM), crude protein (CP) and fiber content of tropical pastures using Sentinel-2 satellite images and machine learning algorithms. Field datasets and satellite images were assessed from an experimental area of Marandu palisade grass (Urochloa brizantha sny. Brachiaria brizantha) pastures, with or without nitrogen fertilization, and managed under continuous stocking during the pasture growing season from 2016 to 2020. Models based on support vector regression (SVR) and random forest (RF) machine-learning algorithms were developed using meteorological data, spectral reflectance, and vegetation indices (VI) as input features. In general, SVR slightly outperformed the RF models. The best predictive models to estimate FM were those with VI combined with meteorological data. For CP and fiber content, the best predictions were achieved using a combination of spectral bands and meteorological data, resulting in R2 of 0.66 and 0.57, and RMSPE of 0.03 and 0.04 g/g dry matter. Our results have promising potential to improve precision feeding technologies and decision support tools for efficient grazing management.


Asunto(s)
Brachiaria , Poaceae , Bovinos , Animales , Poaceae/metabolismo , Brachiaria/metabolismo , Fibras de la Dieta/metabolismo , Algoritmos , Alimentación Animal/análisis
16.
Health Care Women Int ; 34(10): 878-90, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23477658

RESUMEN

Knowledge of sexual health is an important indicator of the development of healthy adolescent sexuality. An evaluation instrument in nursing school practice, whose results can lead to improved sexual health in adolescents, is needed. We conducted this study to undertake rigorous testing of the Sexual Health Knowledge Scale (SHKS) as a means to ensure a reliable and valid quantitative measure of sexual health knowledge among young adolescent females. A panel of experts assessed the content validity of the 40-item measure. Initial testing involved 481 female adolescents (12-14 years old), using principal component factor analysis with varimax rotation and the determination of Cronbach's alpha coefficients. Confirmatory factor analysis (CFA) was conducted using data from an additional sample of 234 female adolescents (12-14 years old). Principal component factor analysis yielded a four-factor solution with eigenvalues greater than 1 that explained 43.40% of the variance. As a result of the analysis of the scale, 22 items were deleted, resulting in an 18-item scale. The CFA identified a second-order factor termed "sexual health knowledge." Goodness-of-fit indices showed an acceptable fit overall with the full model (χ(2)/df (131) = 1.69, RMSEA = 0.054, RMR = 0.013, CFI = 0.92, and GFI = 0.99). We determined that the SHKS is a reliable and valid measure, with good composite reliabilities and goodness-of-fit indices.


Asunto(s)
Pueblo Asiatico/psicología , Conocimientos, Actitudes y Práctica en Salud/etnología , Salud Reproductiva/etnología , Encuestas y Cuestionarios , Adolescente , Niño , Análisis Factorial , Femenino , Humanos , Análisis de Componente Principal , Psicometría/instrumentación , Reproducibilidad de los Resultados , Taiwán
17.
Anim Biosci ; 36(2): 238-247, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36108698

RESUMEN

OBJECTIVE: Recently, indigenous Korean grass Sasa quelpaertensis Nakai (SQ) has garnered much interest as a roughage source for livestock to mitigate its adverse effects on habitat diversity. Thus, the objective of the present study was to evaluate the ruminal fermentation, palatability, and nutrient digestibility of SQ for Korean native beef cattle (Hanwoo) using in vitro rumen fermentation, in situ rumen degradability, and in vivo feeding trials. METHODS: Using in vitro tests with rumen fluid as the inoculum for 48 h, ruminal fermentation of SQ was evaluated and compared with that of other roughage sources commonly used in Korea (i.e., rice straw, Timothy hay, and Italian ryegrass [IRG]). Additionally, an in situ trial 96 h was performed using three cannulated Hanwoo steers. Further, an in vivo trial was performed using eight Hanwoo steers to compare the palatability of SQ with rice straw in total mixed ration (TMR) and forage-concentrate separate feeding conditions. Finally, an in vivo digestibility trial of SQ fed as TMR of two particle sizes was performed with four Hanwoo steers. RESULTS: In vitro and in situ trials revealed that SQ was comparable or superior to rice straw in terms of the ruminal fermentation characteristics of pH, gas production, total volatile fatty acid content, and effective ruminal dry matter digestibility (DMD), although its fermentability was lower than that of Timothy hay and IRG. In the palatability test, steers showed a greater preference for SQ when given as TMR. The total tract DMD of SQ fed as TMR was 75.9%±1.37%, and it did not differ by particle size. CONCLUSION: The feed value of SQ as a roughage source for Hanwoo steers is comparable or superior to that of rice straw, particularly when provided as TMR.

18.
Animals (Basel) ; 14(1)2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-38200872

RESUMEN

An automatic concentrate feeding system (ACFS) divides the day into several intervals, allowing cattle to consume a predetermined amount of concentrate mix per interval. This study investigated the impact of changing these intervals (four vs. six) in an ACFS on its precision in monitoring the feed intake and feeding behavior of fattening Hanwoo steers. The experiment, involving 29 fattening Hanwoo steers (688 ± 43.3 kg of body weight, 24 months old), employed a switchback design with two interval settings: four and six per day. Both individual forage and concentrate intakes and feeding behaviors were automatically recorded; however, the ACFS measured feed supply, not actual intake. The precision of the ACFS's intake recordings was tested by manually assessing feed residuals per visit using video recordings. Although no difference was observed in the concentrate intake (p > 0.05), the six-interval setting reduced concentrate residuals by 0.2 kg per visit (p < 0.05). The increased interval setting also resulted in fewer visits for forage consumption and decreased forage and total dry matter intakes (p < 0.05). In conclusion, the increased interval setting for the ACFS reduced the visit frequency for forage consumption and actual forage consumption while improving the precision of the ACFS's intake recordings.

19.
Animals (Basel) ; 14(1)2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-38200870

RESUMEN

This study investigated the effect of different dietary fat levels in concentrate mixes on the growth performance, rumen characteristics, digestibility, blood metabolites, and methane emissions in growing Hanwoo steers. Thirty steers (386 ± 24.6 kg of body weight [BW]; 12 months old), blocked by BW, were randomly assigned to three dietary treatments with varying fat concentrations in concentrate mix (48, 74, and 99 g of ether extract per kg dry matte [DM]). The fat intake of the low-fat treatment represented 4.15% of the total dry matter intake (DMI), while the medium- and high-fat treatments accounted for 5.77% and 7.23% of total DMI, respectively. Concentrate mix DMI decreased with increasing fat level (p < 0.01). The growth rate and digestibility did not significantly differ based on the fat level (p > 0.05). As the fat level increased, propionate in the total ruminal volatile fatty acids increased, and butyrate and acetate-to-propionate decreased (p < 0.01). Cholesterol in blood serum increased significantly with increasing dietary fat levels (p < 0.01). Methane emissions exhibited a linear decrease with increasing fat level (p < 0.05). In conclusion, elevating fat content in the concentrates up to 100 g/kg DM reduced methane emissions without compromising the growth performance of growing Hanwoo steers.

20.
J Am Chem Soc ; 134(1): 355-66, 2012 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-22106984

RESUMEN

A supported, single-site Lewis acid, ≡SiOB(C(6)F(5))(2), was prepared by water-catalyzed grafting of B(C(6)F(5))(3) onto the surface of amorphous silica, and its subsequent use as a cocatalyst for heterogeneous olefin polymerization was explored. Although B(C(6)F(5))(3) has been reported to be unreactive toward silica in the absence of a Brønsted base, we find that it can be grafted even at room temperature, albeit slowly. The mechanism was investigated by (1)H and (19)F NMR, in both the solution and solid states. In the presence of a trace amount of H(2)O, either added intentionally or formed in situ by borane-induced dehydration of silanol pairs, the adduct (C(6)F(5))(3)B·OH(2) hydrolyzes to afford C(6)F(5)H and (C(6)F(5))(2)BOH. The latter reacts with the surface hydroxyl groups of silica to yield ≡SiOB(C(6)F(5))(2) sites and regenerate H(2)O. When B(C(6)F(5))(3) is present in excess, the resulting grafted boranes appear to be completely dry, due to the eventual formation of [(C(6)F(5))(2)B](2)O. The immobilized, tri-coordinate Lewis acid sites were characterized by solid-state (11)B and (19)F NMR, IR, elemental analysis, and C(5)H(5)N-TPD. Their ability to activate two molecular C(2)H(4) polymerization catalysts, Cp(2)ZrMe(2) and an (α-iminocarboxamidato)nickel(II) complex, was explored.

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