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Background: Angiotensin II induces glomerular and podocyte injury via systemic and local vasoconstrictive or non-hemodynamic effects including oxidative stress. The release of reactive oxygen species (ROS) from podocytes may participate in the development of glomerular injury and proteinuria. We studied the role of oxidative stress in angiotensin II-induced podocyte apoptosis.Methods: Mouse podocytes were incubated in media containing various concentrations of angiotensin II at different incubation times and were transfected with NADH/NADPH oxidase 4 (Nox4) or angiotensin II type 1 receptor for 24 hours. The changes in intracellular and mitochondrial ROS production and podocyte apoptosis were measured according to the presence of angiotensin II.Results: Angiotensin II increased the generation of mitochondrial superoxide anions and ROS levels but suppressed superoxide dismutase activity in a dose- and time-dependent manner that was reversed by probucol, an antioxidant. Angiotensin II increased Nox4 protein and expression by a transcriptional mechanism that was also reversed by probucol. In addition, the suppression of Nox4 by small interfering RNA (siRNA) reduced the oxidative stress induced by angiotensin II. Angiotensin II treatment also upregulated AT1R protein. Furthermore, angiotensin II promoted podocyte apoptosis, which was reduced significantly by probucol and Nox4 siRNA and also recovered by angiotensin II type 1 receptor siRNA.Conclusion: Our findings suggest that angiotensin II increases the generation of mitochondrial superoxide anions and ROS levels via the upregulation of Nox4 and angiotensin II type 1 receptor. This can be prevented by Nox4 inhibition and/or antagonizing angiotensin II type 1 receptor as well as use of antioxidants.

For survival, it is crucial for eating behaviours to be sequenced through two distinct seeking and consummatory phases. Heterogeneous lateral hypothalamus (LH) neurons are known to regulate motivated behaviours, yet which subpopulation drives food seeking and consummatory behaviours have not been fully addressed. Here, in male mice, fibre photometry recordings demonstrated that LH leptin receptor (LepR) neurons are correlated explicitly in both voluntary seeking and consummatory behaviours. Further, micro-endoscope recording of the LHLepR neurons demonstrated that one subpopulation is time-locked to seeking behaviours and the other subpopulation time-locked to consummatory behaviours. Seeking or consummatory phase specific paradigm revealed that activation of LHLepR neurons promotes seeking or consummatory behaviours and inhibition of LHLepR neurons reduces consummatory behaviours. The activity of LHLepR neurons was increased via Neuropeptide Y (NPY) which acted as a tonic permissive gate signal. Our results identify neural populations that mediate seeking and consummatory behaviours and may lead to therapeutic targets for maladaptive food seeking and consummatory behaviours.

BACKGROUND AND AIMS Oxidative stress induced by non-hemodynamic effects of angiotensin II in podocytes participates in the development of glomerular injury and proteinuria. We studied the pathophysiologic roles of oxidative stress in angiotensin II-induced podocyte apoptosis. METHOD Mouse podocytes were incubated in media containing various concentrations of angiotensin II at different incubation times and transfected by Nox4 or AT1R siRNAs or negative control scrambled siRNA for 24 h. The changes of podocyte oxidative stress and apoptosis were observed by confocal imaging, western blotting, real-time PCR, FACS and TUNEL assays according to the presence of angiotensin II. RESULTS Angiotensin II increased the generation of mitochondrial superoxide anions and reactive oxygen species levels but suppressed superoxide dismutase activity that was reversed by probucol, an antioxidant. Angiotensin II also increased NADH/NADPH oxidase 4 protein and expression in a transcriptional mechanism that was also reversed by probucol. In addition, the suppression of NADH/NADPH oxidase 4 by siRNA reduced the oxidative stress induced by angiotensin II. Furthermore, angiotensin II promoted podocyte apoptosis that was reduced significantly by probucol and NADH/NADPH oxidase 4 siRNA, and also recovered by angiotensin II type 1 receptor siRNA. In sum, angiotensin II induced podocyte oxidative stress and apoptosis through NADH/NADPH oxidase 4 and angiotensin II type 1 receptor. CONCLUSION These findings suggest that angiotensin II promotes podocyte mitochondrial oxidative stress, resulting in apoptosis via the upregulation of NADH/NADPH oxidase 4 and angiotensin II type 1 receptor, which could be prevented by NADH/NADPH oxidase 4 inhibition and/or antagonizing angiotensin II type 1 receptor as well as antioxidants.

Food is generally hidden in a natural environment and require free-living animals to search for it. Although such food-seeking behaviors involve motivation and exploration, previous studies examined food-seeking simply by measuring the time spent in the food zone or the frequency of pursuing food-cued context. Moreover, after discovering food, animals need to taste and smell it in order to evaluate their nutritional value or possible toxicity. However, researchers could not easily distinguish food-seeking from food-evaluating behaviors because food was visible or accessible throughout each test. Herein, we describe a behavioral protocol that triggers animals to show the behavioral dynamics of food-seeking (e.g., navigation, nose-digging, and paw-digging) and that exclusively elicits food-seeking without provoking any other food-evaluating behaviors. First, we prepared an open-field box with the floor covered with bedding. After we hid foods under the bedding of each corner, the test mice were habituated in this arena for four days (pre-test phase). On the next day (test phase), they were placed under the same conditions, but the foods previously hidden were removed. This process enabled the mice to perceive their surroundings as a food-hidden environment, which induced the animal to exhibit sustained food-seeking. In conclusion, the protocol presented here is a powerful method for provoking multiple forms of food-seeking and quantifies food-seeking independently from other food-related behavioral stages.

Background/aims Angiotensin II (Ang II) induces podocyte injury resulting in apoptosis in vitro and in vivo. However, the relationship between autophagy and apoptosis in Ang II-induced podocyte injury is unknown and the role of Ang II-induced autophagy in podocyte survival or death remains unclear. We investigated the sequential relationship between autophagy and apoptosis in Ang II-induced podocytes as well as the role of phosphatidylinositide 3-kinase (PI3-kinase). Methods Mouse podocytes were incubated in media containing various concentrations of Ang II and at different incubation times. The changes of podocyte autophagy and apoptosis were observed by electron microscopy, confocal imaging, western blotting, and FACS assay according to the presence of Ang II. Results Ang II enhanced the podocyte expression of the autophagic proteins, LC3A/B-II and beclin-1, and also increased the number of autophagosomes compared with control cells at early phase of 12 hours in a dose-dependent manner. This effect was inhibited by pretreatment with 3-methyladenine (3-MA), a PI3-kinase class III inhibitor. Thereafter, the Ang II-induced enhancement in autophagy decreased, whereas, podocyte apoptosis appeared later at 24 hours in concentration- and time-dependent manners in FACS and TUNEL assays. 3-MA and LY294002, a pan PI3-kinase inhibitor, further increased Ang II-induced podocyte apoptosis. Suppression of autophagy by Atg5 siRNA could induce podocyte apoptosis and further augment high-dose Ang II-induced podocyte apoptosis. Conclusion These findings suggest that Ang II promotes autophagy in podocytes before apoptosis as an early adaptive cytoprotective mechanism for podocyte survival after Ang II treatment, and the transitional imbalance between autophagy and apoptosis causes podocyte injury.

What drives us to eat? It is one of the most fundamental questions in the obesity research field which have been investigated for centuries. Numerous novel in vivo technologies in the neuroscience field allows us to reevaluate the multiple components and phases of food-related behaviors. Focused on the cognitive, executive, behavioral and temporal aspects, food-related behaviors can be distinguished into appetitive phase (food craving→food seeking) and consummatory phase (food consumption). Food craving phase is an internal state or stage in which the animal has the motivation to eat the food but there is no actual food specific behaviors or actions. Food seeking phase entails repeated behaviors with a food searching purpose until the animal discovers the food (or food-related cue) and the approach behavior stage after the discovery of food. Food consumption phase is the step that the animal grabs, chews and intake the food. This review will specifically focus on characteristics and evaluation methods for each phase of food-related behavior in rodent, non-human primates and human.

CD2-associated protein (CD2AP), an adaptor protein, plays several important roles in podocyte function, linking slit diaphragms to actin-based cytoskeleton and sending survival signals. Here, we investigated whether ginseng total saponin (GTS) had a protective role in the changes of podocyte CD2AP protein and podocyte apoptosis under in vitro diabetic conditions. Conditionally immortalized mouse podocytes cultured with normal glucose (5 mM) or high glucose (30 mM) and with or without advanced glycosylation end products were treated with GTS. We found that CD2AP co-localized with the F-actin fibers in podocyte cytoplasm using confocal imaging; however, diabetic conditions caused the podocytes to diminish and conglomerate CD2AP stainings in the peripheral cytoplasm, which were recovered by GTS. Diabetic conditions also suppressed CD2AP protein levels at 6 and 24 h in western blotting. These phenotypical changes of CD2AP protein were mitigated by GTS. Diabetic conditions also induced podocyte apoptosis at 24 h, which were attenuated by GTS. These findings provide a novel mechanism that diabetic conditions induce quantitative and qualitative changes of podocyte CD2AP protein and apoptosis, which would be restored by GTS.

1. Abstract Agouti-related protein (AgRP) has been believed to be the main driver of feeding behaviors ever since its discovery. However, recent studies using fiber photometry and optogenetics proved that feeding behaviors are not directly driven by AgRP neurons (temporal discrepancy between neuronal activity and behavior). To resolve this paradox, we conducted novel multi-phase feeding experiments to scrutinize the dynamics of AgRP. Fiber photometry study showed that AgRP neurons start to deactivate even before the initiation of the food search phase. Using optogenetics, we could prove that the feeding behavior induced by AgRP neuron activation had substantial temporal delay and the feeding behavior was sustained for substantial time even after cessation of optogenetic activation. These results indicate that AgRP neurons are not the direct driver of feeding behavior and another downstream neuron is the driver of feeding behavior. Leptin receptor (LepR) neurons in the lateral hypothalamus (LH). LH LepR neurons were activated before voluntary food search behavior initiation and showed robust increase after food approach behavior. Artificial activation of LH LepR neurons drives food search and food approach behavior. In accordance, chemogenetic activation of LepR neurons increased food search and food approach behaviors. Lastly, slice calcium imaging results showed the possibility that NPY from the AgRP neurons could be the downstream neuromodulator of AgRP neuron, driving LH LepR neuron activation. Overall, our study shows that AgRP neurons are not the direct drivers of feeding behavior, whereas LH LepR neurons directly drive sustained food seeking behavior.

reported from Pyropia species, with identifications based on culture and genetic analysis of the nuclear internal tran scribed spacer (ITS) region. Recent fungal DNA barcoding studies have shown the low taxonomic resolution of the ITS region and suggested the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene as an alternative molecular marker to identify Pythium species. In this study, we applied an analysis of both the ITS and cox1 regions to clarify the taxonomic relationships of Korean Pythium species. From the results, the two closely related Pythium species (P. chondricola and P. porphyrae) showed the same ITS sequence, while the cox1 marker successfully discriminated P. chondricola from P. porphyrae. This is the first report of the presence of P. chondricola from the infected blade of Pyropia yezoensis in Asia. This finding of the algal pathogen provides important information for identifying and determining the distribution of Pythium species. Further studies are also needed to confirm whether P. chondricola and P. porphyrae are coexisting as algal pathogens of Pyropia species in Korea.

【Pyropia, economic red algae species, have been cultivated in Korea (referred to as 'gim'), Japan ('nori'), and China ('zicai') for over 300 years. Vegetable seaweed Pyropia species are sold in the public markets in various forms as commercial seafoods. In Korea, two kinds of Pyropia seafood made with species of Pyropia and Ulva (sea lettuce, referred to as 'parae') are also sold. These are referred to as 'parae-gim' (with Pyropia spp. and U. linza) and 'gamtaegim' (with Pyropia spp. and U. prolifera). There is currently no method for identifying the seaweed species that comprise Pyropia seafood products. Therefore, we developed novel molecular markers to identify Ulva species in commercial Pyropia seafoods. Based on rbcL molecular markers, we identified informative characteristics to discriminate U. linza and U. prolifera as seafood ingredients. Moreover, PCR with 3'-end mismatch primers successfully isolated the specific rbcL sequences of U. linza and U. prolifera from Pyropia seafoods. Therefore, our novel molecular markers will be useful for identifying the ingredient species of commercial seafoods.】

Species of the genera Porphyra and Pyropia are the major seaweed cultivars in Korea, Japan, and China. Genomic data from Porphyra/Pyropia species is now being used for molecular breeding and bioengineering. We determined the complete mitochondrial genome (mtDNA) sequence of Pyropia yezoensis (Bangiales, Rhodophyta) from Korea. Pyropia yezoensis mtDNA was 35,596 bp in size and exhibited high sequence similarity to Py. yezoensis mtDNA reported from China (NC_017837; 41,688 bp). However, the Korean Py. yezoensis differed from the Chinese strain in the presence/absence of introns and intronic open reading frames of the ribosomal RNA large subunit gene (rnl) and cytochrome c oxidase subunit 1 gene (cox1). These differences result in large variations between the mtDNA of the two strains of Py. yezoensis. Moreover, the Korean strain had a single copy of the trnfM–trnQ region, as compared to a duplicate copy of Py. yezoensis (NC_017837). Pyropia mtDNA exhibited unique genetic features at the intra- and interspecies levels. Therefore, mtDNA genomics can provide novel knowledge for red algal molecular systematics and help to differentiate between cultivars of Pyropia species with new molecular markers.

We determined the complete mitochondrial genome (mtDNA, mitogenome) of Pyropia tenera (Bangiales, Rhodophyta). Pyropia tenera mtDNA had a larger size (42,268 bp) than the mtDNA sequences of Porphyra and Pyropia reported previously, and encoded two ribosomal RNA genes [large subunit (rnl), small subunit (rns)], 24 transfer RNAs, four ribosomal proteins, and 17 genes involved in electron transport and oxidative phosphorylation. Moreover, four conserved open reading frames (ORFs) and six intronic ORFs (three in rnl and three in the cox1 gene) were also identified. In comparison with other Porphyra and Pyropia species, Py. tenera had four major structural changes in two gene loss/rearrangement regions [tRNA-Gln(uug)–tRNA-SeC(uca) and tRNA-Ala(ugc)–tRNA-Arg(ucu)] and two different patterns of exon, intron, and intronic ORFs (rnl and cox1). The unique features of Py. tenera mtDNA include the complete sequence of red algal mtDNA for investigating mtDNA evolution and developing molecular markers for species identification. In addition, red algal mtDNA can provide useful genetic information as a genetic reservoir for bioengineering.

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious clinical problem worldwide. Few new drugs are available against MRSA, because it has the ability to acquire resistance to most antibiotics which consequently increases the cost of medication. In the present study, the antibacterial activity of Nardostachytis rhizoma was investigated. The most effective method is to develop antibiotics from the natural products without having any toxic or side effects. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. The use of two drugs in combination is a good alternative to slow the process of developing drug resistance and to restore the effectiveness of drugs that are no longer prescribed. Combination therapy is the most commonly recommended empirical treatment for bacterial infections in intensive care units, where monotherapy may not be effective against all potential pathogens, and for preventing the emergence of resistant. Five clinical isolates (MRSA) were obtained from five different patients at Wonkwang University Hospital (Iksan, South Korea). The other two strains were S. aureus ATCC 33591 (methicillin-resistant strain) and S. aureus ATCC 25923 (methicillin-susceptible strain). Antibacterial activity (minimal inhibitory concentrations, MICs) was determined by broth dilution method, disc diffusion method, MTT test and checkerboard dilution test. Antimicrobial activity of n-hexane fraction of N. rhizoma was significant. Against the seven strains, the disc diffusion test was in the range of 14 to 18 mm and had a MICs ranging from 31.25 to 125 ig/ml. FICI values for n-hexane fraction (HFL) of N. rhizome + ampicillin (AM) and HFL + oxacillin (OX) were 0.1875 and 0.078125-0.09375, showing the increase of synergistic effect. When combined together, these antibiotic effects were dramatically increased. These effective combinations could be new promising agents in the management of MRSA and MSSA. Key words : Nardostachytis rhizoma, synergism, antibacterial, methicillin-resistant Staphylococcus aureus (MRSA).

대형 갈조류 넓미역, Undariopsis peterseniana (Kjellman) Miyabe et Okamura은 우리나라의 제주도 종달리와 우도 사이의 좁은 수로와 가파도 및 청산도에 분포하고 있는 것으로 보고되었으나 (Kang, 1966; Lee, 1998; Lee and Koh, 1991; Lee et al., 1991), 우점 군락은 우도 지역에만 분포하는 것으로 알려져 있다 (Hwang et al., 2010a,b). 넓미역의 분포 지역은 주로 쓰시마 난류의 영향을 직접적으로 받는 지역이며, 저질이 산호조류로 구성된 (Lee, 1998) 수심 15 m 지역에 우점하여 서식하고 있다 (Lee and Koh, 1991; Hwang et al., 2010b). 넓미역은 전통적으로 제주 지역에서 횟감의 쌈용으로 이용되어 왔으나, 자연자원이 급감하면서 수산자원관리법 시행령상의 유용 수산자원으로서 채취금지기간 설정의 대상이 되었다 (Hwang et al., 2010b). 최근 Hwang et al. (2010b)은 보호대상 넓미역의 생태학적 연구를 통해 자연군락에서 생장 및 성숙 주기를 밝혔으며, Hwang et al. (2010a)는 해조류 양식이 주로 이루어지고 있는 전남 완도지역에 넓미역을 도입하여 시험양식에 성공함으로써 대량양식을 위한 적정 생육환경 조건을 구명하였다. 이외에도 남방계 미역 품종인 넓미역의 생리생태학적 특성을 이용하여 미역속간의 교잡연구 등이 수행된 바 있으나 (Migita, 1963; Kang, 1966; Saito, 1972), 지속적인 품종개량이나 산업적인 이용에는 이르지 못하였다. 이는 대형 갈조류군의 경우 배우체와 포자체의 세대교번이 대부분 이형세대교번으로 이루어지기 때문에 이들의 품종개량이나 교잡을 용이하게 하기 위해선 암수배우체의 분리, 배양 및 성숙유도 등의 기법이 요구되나 이와 같은 접근은 현재까지 시도된 바 없다. 유리배우체의 배양에 의한 증식 방법은 소량의 성숙 엽체만으로도 많은 양의 배우체 확보가 가능하며, 확보된 배우체는 무성적으로 대량증식을 통해 지속적인 계대배양이 가능할 뿐 아니라 클론 배우체의 유도를 통한 우량 품종의 교배와 선발육종의 기초를 다질 수 있는 유용한 방법이다 (Wi et al., 2008). 이러한 유리배우체의 대량배양을 위한 재생 및 성숙 유도 조건은 감태 (Wi et al., 2008) 및 곰피 (Hwang et al., 2010b) 등에서 구명된 바 있으나, 넓미역의 경우 현재까지 유리배우체의 분리, 재생 및 성숙 유도 조건이 밝혀진 바 없다. 따라서 이 논문에서는 남방계 미역 품종인 넓미역 유리배우체의 분리, 재생 및 성숙 조건 구명을 통한 유리배우체 대량배양 조건을 밝힘으로써 미역속의 품종개량과 교잡 연구에 기여하고, 나아가서는 보호대상종인 넓미역의 안정적인 종묘수급방안 마련과 자연개체군의 효율적인 보호 방안 마련에 기여하고자 하였다.

This paper proposed a smart-phone based user movement state identification algorithm. Then movement state of the user is identified by calculating the location and moving speed using the GPS sensor, and detailed movement methods are identified by analyzing the data from the Orientation sensor. In this study, two sensors of the smart-phone were used to implement the user movement status identification algorithm and to perform tests. The reference values of the speed and orientation required for the identification of the movement type were defined based on the experimental data. The results of this study showed that the movement type of a smart-phone user can be identified using the user movement state identification algorithm.

Pure lines were isolated from young gametophytic blades of pigmentation and morphological mutants in Porphyra tenera. Growth, blade-shape and photosynthetic pigment content of pure lines were compared with the wild type. Growth of blade length in the wild type (W, R-B), with round shape and brown color, was fastest at 5~10℃ and became slower as temperature increased. The blade-shape of the wild type changed from linear to round as temperature increased. The green type (R-G), with round shape and green color, showed slower growth, and the red type (R-R)with round shape and red colorshowed faster growth than the wild type. The blade-shapes of the green and red types changed from elliptical or linear to round as temperature increased. The phycoerythrin (PE) / phycocyanin (PC) ratio of the green type was markedly lower and the PE/PC ratio of the red type was markedly higher than that of the wild type. The linear type (L-B), with liner shape and brown color, showed faster growth in blade length than the wild type at 10~20℃ and maintained its linear shape at 5~15℃. The content of photosynthetic pigments of the linear type was similar to that of the wild type. Each of the pure lines of pigmentation and morphological mutants that were isolated in the present study showed particular patterns in growth, blade-shape and photosynthetic pigment composition. Therefore, they are expected to be useful as new varieties by themselves and to be available for breeding and biotechnological studies.

곰피 (Ecklonia stolonifera Okamura)는 다시마목 미역과의 다년생 해조로서 점심대의 깊은 곳에서 자라며, 해중림을 구성하는 해조로 연안생태계에서 1차생산자로서의 중요한 기능을 담당하고 있다 (Kang and Yoo, 1993; Brown and Lamare, 1994). 곰피는 우리나라 동해안의 특산으로 부산 연안에서 포항인근까지 분포하였으나 서식지가 점점 확대되어 현재는 남해안 여수 지역까지 자생지가 확인되었다. 대형 갈조류인 곰피는 다시마와 형태적으로 매우 유사한 해조류로 알긴산뿐 아니라 순도가 높은 푸코이단을 다량 함유하고 있으며, 곰피의 푸코이단은 트롬빈 활성이 높아 헤파린의 약 1.4배에 달한다고 알려져 있다 (Lee et al., 1995). 또한 여름철 고수온기 동안 전복의 먹이원으로 이용하거나, 해중림 조성을 통한 연안어장 생산력 증대 및 해양 환경 정화 등에 활용이 가능하다. 대형 갈조류는 산업적 활용성 또는 생태계의 기여도 등에서 높은 잠재성을 가지고 있기 때문에 이들의 원활한 바이오매스 확보에 필수적인 효율적 증식방법 개발을 위한 다양한 시도들이 이루어지고 있다.이형세대교번을 하는 다시마과 해조류는 배우체 세대에서 암․수배우체를 각각 분리하여 무성적으로 증식시킬 수 있으며, 환경조절을 통하여 배우자형성을 유도할 수 있음이 알려져있다 (Luning, 1980). 또한 최근 칠레에서는 전복 먹이원으로써 다시마류의 대량양식에 실내에서 대량 증식시킨 유리 배우체를 이용하는 방안이 개발된 바 있으며 (Westermeier et al., 2006; Edding and Tala, 2003), 국내에서는 감태의 유리배우체 재생 및 성숙 유도 조건이 밝혀진 바 있다 (Wi et al., 2008).현재 우리나라에서 행해지고 있는 미역이나 다시마 등의 양식방법은 매년 성숙된 모조로부터 방출된 유주자를 기질에 채묘하여 양식하는 방법을 사용하고 있으나 이러한 종묘생산 방법을 대규모 곰피 양식에 적용할 경우 많은 양의 모조가 사용되어야 하므로 자연군락의 훼손을 야기할 가능성이 있다 (Wi et al., 2008). 그러나 유리배우체의 배양에 의한 방법은 소량의 성숙 엽체만으로도 많은 양의 배우체 확보가 가능하며, 클론 배우체의 유도를 통한 우량 품종의 교배와 선발육종의 기초를 다질 수 있는 매우 효율적인 방법이라 할 수 있다. 최근 Hwang et al. (2009)은 곰피 유주자 채묘에 의한 양식기법을 확립하여 가이식과 양성조건을 위한 적정조건을 보고한 바 있는데, 곰피의 유리배우체 배양에 의한 안정적인 종묘확보가 이루어질 수 있다면 해중림 조성용 또는 전복 먹이원으로 곰피의 안정적인 양식생산을 꾀할 수 있을 것이다. 따라서 본 연구에서는 곰피 암수 배우체의 분리 배양 및 생장과 성숙 조건을 파악하여 안정적인 유리배우체의 배양조건을 확립함으로써 효율적인 곰피 양식의 기초를 마련하고자 하였다.

The effects pH and salinity on the brown alga Sargassum fulvellum were investigated in the context of the removal of two major associated animals, Caprella scaura and Gammaropsis utinomi. Optimum quantum yield (Fv/Fm) of S. fulvellum was also examined in the same experimental conditions as an index of stress. Experiments on pH and salinity tolerances of the two animal species indicated that mortality was more than 80% at extremes of pH (2, 3, 4, 10, 11, 12) and salinity (0, 3.5, 7, 10, 44 psu) after a 5 min treatment. Lethal time (LT50) from pH 2 to pH 4 was less than 90 sec in C. scaura, and less than 70 sec in G. utinomi. From 0 to 10 psu, LT50 was less than 20 sec in C. scaura and less than 60 sec in G. utinomi. The quantum yield of S. fulvellum was not significantly different from controls within the pH range 4~10, and within the salinity range of 7-40 psu. When exposed to pH and salinity conditions outside these ranges, the effect of these factors on the removal of two animal species was higher, but quantum yield was highly reduced. These results indicate that the optimal conditions for removing the animal species without affecting optimum quantum yield were pH 4-10, and salinities 7-10 psu and 44 psu.

Nuclear SSU and ITS1 rDNA and plastid rbcL sequences were determined to identify the seven samples of Porphyra cultivated by means of natural seeding on the southwest coast of Korea and analyzed to access the phylogenetic relationships of them with the natural populations of P. tenera and P. yezoensis from Korea and Japan. SSU, rbcL and ITS1 data from 18, 21 and 31 samples, respectively, including previously published sequences were investigated in the study. Results from our individual and combined data indicated that the seven samples were all P. yezoensis and the entities except one from Muan 2 aquafarm strongly grouped together with the natural populations of P. yezoensis from the south and the west coast of Korea. The sample from Muan 2 seems to be derived from a strain of P. yezoensis introduced from Japan by Porphyra farmers, based on DNA sequence data.

Aryl methyl and aryl phenyl sulfides were prepared by the reaction of arenediazonium tetrafluoroborates with trimethyl(methylthio)- and trimethyl(phenylthio)silanes, respectively. In the latter case, addition of cupric sulfide was found to increase the yields. The main by-products were protodediazoniated products and diphenyl disulfide, which can be removed by treatment with aqueous sulfide and a base.

Buckminsterfullerene reects with aromatic benzene derivatives in the presence of Lewis acids such as aluminum trichloride or aluminum tribromide to give Friedel-Crafts fullerenation products. Polyhalogenated fullerenes also react with aromatic compounds to afford fullerylated aromatic compound under the Friedel-Crafts reaction conditions.

Heat shock proteins and molecular chaperones are key components contributing to survival in the abiotic stress response. Porphyra seriata grows on intertidal rocks exposed to dynamic environmental changes associated with the turning tides, including desiccation and heat stress. Analysis of the ESTs of P. seriata allows us to identify the nine HSP cDNAs, which are predicted to be PsHSP90, three PsHSP70, PsHSP40 and PsHSP20, and three 5′-truncated HSP cDNAs. RT–PCR results show that most of the PsHSP transcripts were detected under normal cell growth conditions as well as heat stress, with the exception of two cDNAs. In particular, PsHSP70b and PsHSP20 transcripts were upregulated by heat stress. When the putative mitochondrial PsHSP70b was introduced and overexpressed in Chlamydomonas, transformed Chlamydomonas evidenced higher rates of survival and growth than those of the wild type under heat stress conditions. Constitutive overexpression of the PsHSP70b gene increases the transcription of the HSF1 as well as the CrHSP20 and CrHSP70 gene. These results indicate that PsHSP70b is involved in tolerance to heat stress and the effects on transcription of the CrHSP20 and CrHSP70 genes.

Chlorotrimethylsilane reacts with chromic anhydride to form a very reactive neutral chromium (Ⅵ) oxidizing agent. The active oxidizing species is not trimethylsilyl chlorochromate as was previously reported but chromyl chloride generated in equilibrium concentration. This oxidizing agent was proved very suitable for benzylic oxidations of toluenes and alkylbenzenes to benzaldehydes and aralkyl ketones. Dichlorodimethylsilane and trichlormethylsilane also react with chromic anhydride to form chromyl chloride in an equilibrium concentration.