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1.
Muzafar A. Kanjwal Nasser A. M. Barakat Faheem A. Sheikh Woo-il Baek Myung Seob Khil Hak Yong Kim 《Fibers and Polymers》2010,11(5):700-709
As titanium oxide is a well-known photocatalyst, we investigated the effects of silver content and nanostructural morphology
on the photocatalytic degradation of two dyes, methylene blue and rhodamine B. Two nano-formulations were utilized, including
nanofibers and nanoparticles. Silver-grafted titanium oxide nanofibers were synthesized using the electrospinning of silver
nitrate/titanium isopropoxide/poly(vinyl acetate) sol-gel. The nanoparticulate form was obtained by calcination of a ground
powder prepared from the same electrospun sol-gel. The results affirmed the advantage of the silver-grafted titanium oxide
nanostructures over the silver-free ones. Increasing the silver content in the nanofibers led to increases in their surface
area, which is an important parameter in heterogeneous catalytic chemical reactions. Therefore, the results strongly suggest
the use of silver-grafted titanium oxide in a nanofibrous form. These results further support utilizing Agloaded titanium
oxide nanofibers as a photocatalyst. 相似文献
2.
Inja Yeon Mi Young SongMyoung Ho Sohn Hak Jin HwangYang Jae Im Do Hoon KimHee Won Park Chang Ik Zhang 《Fisheries Research》2011,112(3):179-188
Landings in the blue crab, Portunus trituberculatus, fishery in Korean waters of the Yellow Sea have declined substantially from 11,000 t in the 1980s to 2,300 t in 2004. Blue crab habitat quality in the Yellow Sea has been degraded by anthropogenic activities including sand mining, land reclamation, and coastal pollution. Various traditional management measures have been implemented, including closed seasons during spawning and size limits, but these measures alone have been unsuccessful to conserve blue crab stocks. Consequently, a total allowable catch and a stock-rebuilding program using an ecosystem-based management approach were implemented in 2003 and 2006, respectively to rebuild blue crab stocks and restore habitats. This program involved assessment of both blue crab stock status and trammel-net fishery impacts at an ecosystem-level using an ecosystem-based fisheries assessment method (
[Zhang et al., 2009] and [Zhang et al., 2010]), which considered fishery data from catch and effort time-series, crab population biology, and ecosystem characteristics, including habitats and environmental conditions. Recent (2008) management status indices have shown significant positive change compared to conditions in 2000 with respect to sustainability of the stock and fishery and with regards to biodiversity and ecosystem habitat quality. 相似文献
3.
发酵过程生物参数的在线检测,是获得发酵过程生物信息的重要手段,也是进行合理最优控制的基础。但是,目前许多生物量只能离线检测,不能够为实时的控制系统利用。因此提出了基于图像处理技术的生物反应器浓度在线检测系统,系统由反应液循环与控制装置、反应液浓度光学检测装置、图像采集与处理装置、计算机以及相应的处理软件组成。通过与分光光度计的实验比较,证实了所设计的系统可以用于生物反应器浓度的在线测量,为实现发酵过程生物参数的在线检测提供了值得借鉴的设计思路和实现方法。 相似文献
4.
Hem Raj Pant Bishweshwar Pant Chan Hee Park Han Joo Kim Dong Su Lee Leonard D. Tijing Bo Sang Hwang Hak Yong Kim Cheol Sang Kim 《Fibers and Polymers》2013,14(6):970-975
In this work, the reduced graphene oxide (RGO) sheets were effectively uploaded through nylon-6 fibers using combined process of electrospinning and hydrothermal treatment. Good dispersion of graphene oxide (GO) with nylon-6 solution could allow to upload GO sheets through nylon-6 fibers and facilitate the formation of spider-wave-like nano-nets during electrospinning. GO sheets present on/into nylon-6 spider-wave-like nano-nets were further reduced to RGO using hydrothermal treatment. The impregnated GO sheets into nylon-6 nanofibers and their reduction during hydrothermal treatment were confirmed by FE-SEM, TEM, FT-IR and Raman spectra. The electrical characteristics of pristine nylon-6, GO/nylon-6 and RGO/nylon-6 nanofibers were investigated and it was found that RGO/nylon-6 composite mat had better electrical conductivity than others. The formation of spider-wave-like nano-nets as well as indirect route of incorporation of RGO sheets on electrospun nylon-6 mat may open a new direction for future graphene/polymer electronics. 相似文献
5.
Akira Shigematsu Nobuya Mizoue Kumiko Ide Kakada Khun Muthavy Pheng Shigejiro Yoshida Katsuhisa Kohroki Noriko Sato 《New Forests》2011,42(2):149-162
We estimated the production of rubberwood from 1996 to 2011 in Cambodia. We employed data from interview surveys with three
rubberwood processing companies and statistics from estate rubber plantations and wood retailing companies. The result was
that the end use of rubberwood in Cambodia was the sawntimber products, being exported to Vietnam and China. The yield rate
from rubberwood stumpage into sawn timber was between 11.6 and 14.9%, closely matching the rates of Malaysia and Thailand.
The average production of rubberwood roundwood from 1996 to 2011 was 254,697 m3/year, of which sawn timber as well as residuals in secondary processing was 84,559 and 170,138 m3/year, respectively. Although the timber production of Cambodia has declined sharply due to the strict restriction of natural
forest logging, rubberwood could explain more than 60% of the domestic industrial roundwood production from 2000. We suggest
the necessity of monitoring the expansion of rubber plantations in new rubber producing countries and linking the rubberwood
production with the regional wood resource management. 相似文献
6.
Seung Hak YANG Tohru MATSUI Hiroyuki KAWACHI Tomoya YAMADA Naoto NAKANISHI Hideo YANO 《Animal Science Journal》2003,74(1):17-21
ABSTRACT This experiment was conducted to investigate leptin mRNA expression, adipocyte size, and their relationship in several adipose tissues of fattening steers. Subcutaneous, perirenal, intermuscular and intramuscular adipose tissues were collected from three crossbred steers (Japanese Black cattle X Holstein) aged 21 months. The mRNA level and adipocyte diameter were determined in these adipose tissues. The intramuscular adipose tissue had a lower leptin mRNA level than the intermuscular and perirenal adipose tissues (P < 0.05). Leptin mRNA level was lower in the subcutaneous depot than in the intermuscular depot (P < 0.05). Adipocyte diameter was larger in the intermuscular adipose tissue than in the subcutaneous and intramuscular adipose tissues (P < 0.05). Leptin mRNA level was positively correlated with adipocyte diameter (r2 = 0.81, P < 0.05). These results suggest that the cattle have fat depot‐specific differences in leptin gene expression, which are a result of a difference in adipocyte size. 相似文献
7.
Chang J Jung JH Yoon J Choi MC Park JH Seo KM Jeong SM 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(6):641-643
A nine-month-old domestic short haired cat was admitted with the history of acute vomiting, depression and shivering. Abdominal ultrasonography revealed minimum enlargement of the right uterine horn filled with anechoic fluid. On excretory urography, functionally and anatomically normal, enlarged left kidney was found, but right kidney was absent. It was preliminary diagnosed as hydrometra with right renal agenesis. Aiming at the correction of hydrometra, we performed ovariohysterectomy. During spaying, we found a missing segment of distal part of the right uterine horn and absence of ipsilateral kidney and ureter. Compressed uterine structure and segmental aplasia of right uterine horn were found in histopathological investigation. Taken together, it was diagnosed as a segmental aplasia of uterine horn with ipsilateral renal agenesis. 相似文献
8.
Joo Youn Oh † ‡ Mee Kum Kim † ‡ Hyun Ju Lee † ‡ Jung Hwa Ko † ‡ Won Ryang Wee † ‡ Jin Hak Lee † ‡ 《Veterinary ophthalmology》2009,12(S1):50-56
Objective Although variations exist between species with respect to outcomes after cryopreservation, little is known about the differences in the susceptibility of the corneal stroma to cryoinjury. We performed this study to investigate freeze–thaw-induced damage in keratocytes and collagen in rabbit, pig, and human corneas.
Animals studied Rabbit, pig, and human.
Procedures We prepared 250-μm-thick anterior stroma from rabbit, pig, and human corneas after scraping off the epithelium and endothelium. Each 250-μm-thick corneal stroma without epithelium was placed in a 50-mL tube, frozen with liquid N2 for 15 min and taken out to thaw rapidly at 37 °C. This procedure of rapid freezing and thawing was repeated three times. Differences between the species with respect to cells and collagen structures were examined using hematoxylin–eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and transmission electron microscopy (TEM). We orthotopically transplanted the pig and rabbit corneal transplants after the triple freeze–thaw cycle into rabbit eyes and evaluated graft survival.
Results On gross examination, rabbit corneas became opaque after the triple freeze–thaw procedure, while pig and human corneas remained transparent. Histologically, keratocytes were apoptotic on TUNEL assay and TEM in rabbit, pig, and human corneas. Collagen fibrils were fragmented and the arrangement of collagen fibrils was severely disturbed in rabbit corneas on H&E staining and TEM; collagen was well preserved in pig and human corneas. Rabbit corneal stroma underwent autolysis after transplantation, whereas the pig corneal stroma remained clear for 1 month.
Conclusions Our study showed that rabbit corneal stroma was more susceptible to freeze–thaw injury than pig and human corneas. 相似文献
Animals studied Rabbit, pig, and human.
Procedures We prepared 250-μm-thick anterior stroma from rabbit, pig, and human corneas after scraping off the epithelium and endothelium. Each 250-μm-thick corneal stroma without epithelium was placed in a 50-mL tube, frozen with liquid N
Results On gross examination, rabbit corneas became opaque after the triple freeze–thaw procedure, while pig and human corneas remained transparent. Histologically, keratocytes were apoptotic on TUNEL assay and TEM in rabbit, pig, and human corneas. Collagen fibrils were fragmented and the arrangement of collagen fibrils was severely disturbed in rabbit corneas on H&E staining and TEM; collagen was well preserved in pig and human corneas. Rabbit corneal stroma underwent autolysis after transplantation, whereas the pig corneal stroma remained clear for 1 month.
Conclusions Our study showed that rabbit corneal stroma was more susceptible to freeze–thaw injury than pig and human corneas. 相似文献
9.
Hak Jin Kim Yong Woo Kim In Sook Lee Jong Woon Song Yeon Joo Jeong Seon Hee Choi Kyung Un Choi Kuen Tak Suh Byung Mann Cho 《Acta veterinaria Scandinavica》2009,51(1):30
Background
To test the hypothesis that triolein emulsion will increase vascular permeability of skeletal muscle.Methods
Triolein emulsion was infused into the superficial femoral artery in rabbits (triolein group, n = 12). As a control, saline was infused (saline group, n = 18). Pre- and post-contrast T1-weighted MR images were obtained two hours after infusion. The MR images were qualitatively and quantitatively evaluated by assessing the contrast enhancement of the ipsilateral muscles. Histologic examination was performed in all rabbits.Results
The ipsilateral muscles of the rabbits in the triolein group showed contrast enhancement, as opposed to in the ipsilateral muscles of the rabbits in the saline group. The contrast enhancement of the lesions was statistically significant (p < 0.001). Histologic findings showed that most examination areas of the triolein and saline groups had a normal appearance.Conclusion
Rabbit thigh muscle revealed significantly increased vascular permeability with triolein emulsion; this was clearly demonstrated on the postcontrast MR images. 相似文献10.
Faheem A. Sheikh Nasser A. M. Barakat Muzafar A. Kanjwal S. J. Park Hern Kim Hak Yong Kim 《Fibers and Polymers》2010,11(3):384-390
Gallium arsenide (GaAs) does have superior electronic properties compared with silicon. For instant, it has a higher saturated
electron velocity and higher electron mobility. Weak mechanical properties and high production cost are the main drawbacks
of this interesting semiconductor. In this study, we are introducing production of GaAs nanofibers by electrospinning methodology
as a very low cost and yielding distinct product technique. In general, nano-fibrous shape is strongly improving the physical
properties due to the high surface area to volume ratio of this nanostructure. The mechanical and environmental properties
of the GaAs compound have been modified since GaAs nanofibers have been produced as a core inside a poly(vinyl alcohol) (PVA)
shell. GaAs/PVA nanofibers were prepared by electrospinning of gallium nitrate/PVA solution in presence of arsenic vapor.
The whole process was carried out in a closed hood equipped with nitrogen environment. FT-IR, XPS, TGA and UV-Vis spectroscopy
analyses were utilized to confirm formation of GaAs compound. Transmission electron microscope (TEM) analysis has revealed
that the synthesized GaAs compound is crystalline and does have nano-fibrous shape as a core inside PVA nanofibers. To precisely
recommend the prepared GaAs nanofiber mats to be utilized in different applications, we have measured the electric conductivity
and the band gap energies of the prepared nanofiber mats. Overall, the obtained results affirmed that the proposed strategy
successfully remedied the drawbacks of the reported GaAs structures and did not affect the main physical properties of this
important semiconductor. 相似文献