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To evaluate vaccine-induced humoral and cell-mediated immunity at 6 months after completion of two doses of BNT162b2 vaccination, immunoglobulin G against SARS-CoV-2 spike protein (SP IgG), 50% neutralizing antibody (NT

[Purpose] This study aimed to clarify the effect of an adaptation of a deviation of the visual field in three axes on spatial cognition in patients with unilateral spatial neglect and distorted spatial perception in three dimensions. [Participants and Methods] Fifteen patients with cerebrovascular disease and symptoms of unilateral spatial neglect were included. Forty-eight pointing movements with a camera attached to a head-mounted display changed in three axes were compared with the control condition in which the camera was deflected only in the horizontal plane as with the prism adaptation. The main outcome measures were subjective straight-ahead pointing, line bisection, line cancellation, and star cancellation. [Results] The head-mounted display adaptive therapy was performed under conditions that varied in all three axes. The results indicated that it was possible to deflect the subjective straight-ahead pointing position to the lower left direction. [Conclusion] In contrast to the prism adaptation, which deflects the visual field in a single axis in the horizontal plane, the tri-axial adaptation corrected the median cognition in the left-right direction as well as the cognition of the body center, including the vertical direction.

Plasma glutamate concentrations are constant despite dynamic changes in diets. Most likely, virtually all the dietary glutamate is metabolized in the gut. The present study investigated permeability and metabolism of dietary glutamate in a Caco-2 intestinal epithelial cell layer model by tracing the fate of [U-13C] or [15N]glutamate added to the apical medium. For comparison, several other labelled essential and non-essential amino acids were tested as well. Almost all the labelled glutamate in the apical medium (98% and 96% at 24 h of the culture, respectively) was incorporated in the cell layer, while it barely appeared at the basolateral side, indicating an almost complete utilization of glutamate. Indeed, the 13C was incorporated into alanine, proline, ornithine, and glutamine, and the 15N was incorporated into alanine, glutamine, ornithine, proline, branched chain amino acids and also found as ammonia indicative of oxidation. In contrast, substantial apical-to-basolateral transport of amino acids (8–85% of uptake) other than glutamate and aspartate was evident in studies using amino acid tracers labelled with 13C, 15N or D. These results suggest that the intestinal epithelial cell monolayer utilizes dietary glutamate which adds to maintaining glutamate homeostasis in the body.

The uncontrolled spread of the COVID-19 pandemic has led to the emergence of different SARS-CoV-2 variants across the globe. The ongoing global vaccination strategy to curtail the COVID-19 juggernaut, is threatened by the rapidly spreading Variants of Concern (VOC) and other regional mutants, which are less responsive to neutralization by infection or vaccine derived antibodies. We have previously developed the hiVNT system which detects SARS-CoV-2 neutralizing antibodies in sera in less than three hours. In this study, we modify the hiVNT for rapid qualitative screening of neutralizing antibodies (nAb) to multiple VOC of SARS-CoV-2, and assess the neutralizing efficacy of the BNT162b2 mRNA vaccine on seven epidemiologically relevant SARS-CoV-2 variants. Here we show that the BNT162b2 mRNA vaccine can activate humoral immunity against the major SARS-CoV-2 mutants that are currently in circulation. Albeit a small sample size, we observed that one dose of vaccine was sufficient to elicit a protective humoral response in previously infected people. Using a panel of seven SARS-CoV-2 variants and a single prototype virus, our modified hiVNT would be useful for large-scale community wide testing to detect protective immunity that may confer vaccine/immune passport in the ongoing COVID-19 pandemic.

Previously, it was difficult to detect mild neglect or a lack of stimulus-driven attention in patients using conventional assessments such as the Behavioral Inattention Test, usually performed on patients with unilateral spatial neglect. Here, we developed a method that randomly generates balloons in the left-right, up-down, and near-far spaces on a monitor using a head-mounted display. A head-mounted display can be used as an objective tool to evaluate and treat mild neglect symptoms by quantifying how quickly and accurately a patient can perceive the appearing balloons. In this study, we evaluated a lack of stimulus-driven attention case that was undetected by the paper and pencil test. We could identify mild neglect with our virtual reality method, as later confirmed using the Catherine Bergego scale. In addition to using virtual reality in a three-dimensional space to effectively detect mild neglect, this method can be used for treatment. After repeated practice under a tilted background space condition, the patient demonstrated a reduction in the time needed to perceive the appearing balloons, suggesting a therapeutic effect., 東京都立大学学位論文甲第1160号 副論文

BackgroundLevels of 50% neutralizing titer (NT50) reflect a vaccine-induced humoral immunity after the vaccination against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Measurements of NT50 are difficult to implement in large quantities. A high-throughput laboratory test is expected for determining the level of herd immunity against SARS-CoV-2.MethodsWe analyzed samples from 168 Japanese healthcare workers who had completed two doses of the BNT162b2 vaccine. We analyzed immunoglobulin G (IgG) index values against spike protein (SP) using automated chemiluminescent enzyme immunoassay system AIA-CL and analyzed the background factors affecting antibody titer. SP IgG index was compared with 50% neutralization titers.ResultsThe median SP IgG index values of the subjects (mean age = 43 years; 75% female) were 0.1, 1.35, 60.80, and 97.35 before and at 2, 4, and 6 weeks after the first dose, respectively. At 4 and 6 weeks after the first dose, SP IgG titers were found to have positive correlation with NT50 titer (r=0.7535 in 4 weeks; r=0.4376 in 6 weeks). Proportions of the SP IgG index values against the Alpha, Beta, Gamma, and Delta variants compared with the original strain were 2.029, 0.544, 1.017, and 0.6096 respectively. Older age was associated with lower SP IgG titer index 6 weeks after the first dose.ConclusionsSP IgG index values were raised at 3 weeks after two doses of BNT162b2 vaccination and have positive correlation with NT50. SP IgG index values were lower in the older individuals and against Beta and Delta strain.

To evaluate vaccine-induced humoral and cell-mediated immunity at 6 months post BNT162b2 vaccination, immunoglobulin G against SARS-CoV-2 spike protein (SP IgG), 50% neutralizing antibody (NT50), and spot-forming cell (SFC) counts were evaluated by interferon-γ releasing ELISpot assay of 98 healthy subjects (median age, 43 years). The geometric mean titers of SP IgG and NT50 decreased from 95.2 (95% confidence interval (CI) 79.8–113.4) to 5.7 (95% CI 4.9–6.7) and from 680.4 (588.0–787.2) to 130.4 (95% CI 104.2–163.1), respectively, at 3 weeks and 6 months after the vaccination. SP IgG titer was negatively correlated with age and alcohol consumption. Spot-forming cell counts at 6 months did not correlate with age, gender, and other parameters of the patients. SP IgG, NT50, and SFC titers were elevated in the breakthrough infected subjects. Although the levels of vaccine-induced antibodies dramatically declined at 6 months after vaccination, a certain degree of cellular immunity was observed irrespective of the age.

The aim of the present study was to investigate the psychological effects of the COVID-19 outbreak and associated factors on hospital workers at the beginning of the outbreak with a large disease cluster on the Diamond Princess cruise ship. This cross-sectional, survey-based study collected demographic data, mental health measurements, and stress-related questionnaires from workers in 2 hospitals in Yokohama, Japan, from March 23, 2020, to April 6, 2020. The prevalence rates of general psychological distress and event-related distress were assessed using the 12-item General Health Questionnaire (GHQ-12) and the 22-item Impact of Event Scale-Revised (IES-R), respectively. Exploratory factor analysis was conducted on the 26-item stress-related questionnaires. Multivariable logistic regression analysis was performed to identify factors associated with mental health outcomes for workers both at high- and low-risk for infection of COVID-19. A questionnaire was distributed to 4133 hospital workers, and 2697 (65.3%) valid questionnaires were used for analyses. Overall, 536 (20.0%) were high-risk workers, 944 (35.0%) of all hospital workers showed general distress, and 189 (7.0%) demonstrated event-related distress. Multivariable logistic regression analyses revealed that ‘Feeling of being isolated and discriminated’ was associated with both the general and event-related distress for both the high- and low-risk workers. In this survey, not only high-risk workers but also low-risk workers in the hospitals admitting COVID-19 patients reported experiencing psychological distress at the beginning of the outbreak.

Peptide amphiphiles are one of the most promising materials in the biomedical field, so much effort has been devoted to characterizing the mechanism of their self-assembly and thermosensitive gelation. In this work, vapor pressure osmometry measurements were carried out to parameterize the thermosensitivity of interactions between peptide amphiphiles in an aqueous solution. The osmometry measurement verified that the peptides became more hydrophobic as temperature increased, which was quantitatively described with the Flory–Huggins χ parameter. Thereafter, a coarse-grained molecular model was used to simulate peptide amphiphiles dissolved in an aqueous solution. The temperature sensitive coarse-grained parameter aHW, which is the repulsive force between the hydrophilic head of the peptide amphiphile and water was estimated from the aforementioned experimentally obtained χ. Furthermore, the effects of concentration and temperature on the self-assembly behavior of peptide amphiphiles were quantitatively studied by dissipative particle dynamics. The simulation results revealed that aHW plays an important role in self-assembly characteristics and in the resulting microstructure of the peptide amphiphiles, which coincides with previous experimental and computational findings. The methodology in quantitatively linking the coarse-grained parameter from experiment and theory provides a sensible foundation for bridging future simulation studies with experimental work on macromolecules.

Objective: The purpose of this study was to verify the effect on spatial perception in healthy young subjects of an unconscious leftward optical shift created by a head-mounted display (HMD) with an offset camera. Methods: We recruited 40 healthy right-handed adults who were divided into four groups according to the hand used in the tests and the visual direction displayed by the HMD (centered or 10° left). Each of the four groups (n = 10) undertook line bisection tasks across four combinations of variables: using a finger/stick or a mouse to point at a touch panel located 60 or 120 cm away from the subject. Results: According to the results, regardless of the hand used, when the index finger or a stick was used (reaching condition), the line bisection point was displaced significantly to the left of the center. Additionally, a major left-displacement trend was observed in the short-distance reaching task, which did not require the use of a stick. In contrast, the long-distance task required a stick to be used, and the left displacements were all smaller than those for the short-distance tasks that used the index finger. Conclusion: This finding may be explained by the subjects having sufficient experience coordinating hand and eye movements in the condition where they used their dominant hand and reached with their own arms without using a stick., 東京都立大学学位論文甲第1160号 副論文

This paper describes a numerical method for a transient quantum drift-diffusion model arising in semiconductor devices. The discretization method is presented with emphasis on adaptive time discretization. An adaptive time step algorithm is constructed by introducing the derivative of the free energy of the system, which has an essential property to understand the carrier behavior of the time-dependent problems. The algorithm is verified with switching characteristics of one-dimensional n+–n–n+ silicon diodes. It is shown that the time step is adapted to the switching characteristics. The new algorithm significantly reduces the total number of time steps.

The shrinkage of low-density polyethylene (LDPE) foam obtained by the extrusion foaming method using isobutene as a blowing agent is suppressed and the dimensional stability is improved by blending with a permeation modifier of stearyl stearamide. To understand the mechanism involved in the modification of the permeability, the gas permeability and the surface structure of LDPE—stearyl stearamide blend films aged for various periods is investigated by using a gas transmission rate tester, scanning electron microscopy (SEM), attenuated total reflectance-infrared spectroscopy (ATR-IR), and grazing incidence X-ray diffraction (GIXD). After aging, a thin layer consisting of distorted particles appears at the surface of the blend film. The amount of stearyl stearamide at the surface increases as the aging time increases. These results suggest that the stearyl stearamide bleeds out to the surface of the film during aging. Gas permeability is suppressed by increasing the amount of stearyl stearamide that bleed out at the surface due to a decrease in solubility, and the permeability of isobutane becomes less than that of air over time. Such modification of permeability improves the dimensional stability of the LDPE foam in the extrusion and post-extrusion aging processes.

界面活性剤をブレンドしたポリエチレンフィルムを熱処理することによる表面構造の変化を調べた．全反射赤外吸収スペクトル(ATR-IR)法および微小角 X 線回折(GIXD)測定によりフィルム表面の構造を調べたところ，フィルム表面に存在する界面活性剤の量が熱処理に伴い増加したことから，熱処理によりフィルム表面へ界面活性剤がブリードアウトすることがわかった．ブリードアウトさせたフィルム表面を原子間力顕微鏡(AFM)により観察したところ，界面活性剤 4 から 20 分子の長さに相当する階段状のモザイク形状をした界面活性剤の結晶析出物が見いだされた．また，得られたフィルム表面は親水性を示すことが接触角測定により明らかになった．このような界面活性剤のブリードアウトによる表面構造の変化が，フィルム試料のガス透過性を大きく変化させることが示唆された．

Histone tail domains play important roles in cellular processes, such as replication, transcription, and chromosome condensation. Histone H2A has one central and two tail domains, and their functions have mainly been studied from a biochemical perspective. In addition, analyses based on visualization have been employed for functional analysis of some chromatin proteins. In this study, we analyzed histone H2A mobility in vivo by two-photon FRAP, and elucidated that the histone H2A N- and C-terminal tails regulate its mobility. We found that histone H2A mobility was increased following treatment of host cells with a histone deacetylase inhibitor. Our results support a model in which core histone tails directly regulate transcription by interacting with nucleosome DNA via electrostatic interactions.

背景:日常的には鏡検する機会の少ない副甲状腺腫瘍の細胞診を経験したので, 副甲状腺過形成および他に鑑別を要する甲状腺疾患の細胞像との比較検討を試みた.症例:49歳, 女性.46歳時に人工透析に伴う腎性副甲状腺機能亢進症を指摘され, 副甲状腺全摘が行われた際, その一部が甲状腺周囲筋肉内に自家移植された.3年後, 甲状腺右葉から峡部にかけて鶏卵大の低エコー領域を認めたため穿刺吸引細胞診を施行, 小型円形核に粗顆粒状の核クロマチンを有する細胞のシート状または重積性のある集塊が得られた.既往所見等から副甲状腺関連病変の再発を疑ったが, 細胞像のみからは良悪性の鑑別は困難であり, 手術材料の組織学的所見および免疫染色所見より, 自家移植された過形成組織を母地として発生した副甲状腺腫瘍と考えられた.結論:副甲状腺疾患の良悪性の細胞診での判定は困難であるが, 副甲状腺疾患の既往や甲状腺疾患細胞の鑑別点に注意することにより診断が可能と思われた.

Studying intact organelles and their function in a living cell is essential to understand cell dynamics. Femtosecond laser pulses in the near-infrared region have potential applications in nanosurgery in cell biology. We investigate the disruption of subcellular organelles in living cells by focusing femtosecond laser pulses inside the cells. When intense femtosecond laser pulses are tightly focused at the targeted organelles, the intensity around the focal volume can become high enough to result in a permanently damaged region in the cell with sub-micron size. Femtosecond laser disruption offers precise control of material removal or modifications of organelles in the cell. The subcellular disruption of mitochondria in living cells was demonstrated by restaining experiments. Femtosecond laser-based nanosurgery has the possibility to provide information on the function and dynamics of organelles in living cells.

目的:高分化型脂肪肉腫の細胞学的特徴を明らかにし, さらに脱分化型脂肪肉腫の細胞像および脂肪腫との鑑別点についても検討した.方法:穿刺吸引細胞診を行った高分化型脂肪肉腫 (脂肪腫類似型) 5例, 脱分化型脂肪肉腫2例, 大型の脂肪腫6例について, Papanicolaou染色およびMay-GrUenwald Giemsa染色標本を用いて, 細胞学的特徴を検討した.成績:脂肪肉腫7例すべてに, 2核の異型細胞が出現しており, 高分化型脂肪肉腫の細胞学的特徴と考えられた. May-Gruenwald Giemsa染色標本では, この2核細胞は裸核状を呈することが多いが, ときに細胞質内に空胞を認めた. 一方, 大型の異型多核細胞が高分化型3例, 脱分化型2例にみられた. 脂肪腫6例中2例にも少数の異型多核細胞を認めたが, 高分化型脂肪肉腫にみられるものに比べ異型性の程度はより軽微であった.結論:高分化型脂肪肉腫および脱分化型脂肪肉腫7例すべてにみられた2核細胞は, これらの細胞学的診断に有用な所見であると思われた. しかし, 脂肪腫の2例にもわずかに出現しており, 組織学的にも同様の所見であったこの2例は厳重なfollow upを必要とすると考えられる.細胞診断において, 2核および大型多核異型細胞の有無のみで高分化型脂肪肉腫と診断するのではなく, 脂肪腫においても出現する可能性を考慮に入れて診断することが重要である.

The addition of 2,2,2-trifluoroethanol (TFE) induces both the transition from β-sheet to α-helix structure of peptides and disassembly of wormlike micelles of peptide amphiphiles. The hierarchical ...

Moldy and split peanut kernels were separated from peanuts exported from Brazil, Sudan, India and Taiwan by visual inspection. The remaining peanuts from Brazil, Sudan and India were roasted lightly and the skins were removed. Stained peanuts were separated from the others. Aflatoxin was detected in moldy and stained peanuts. There was a positive correlation between % of aflatoxin-contaminated peanut kernels and aflatoxin B1 concentration in whole samples. Aflatoxin concentration of moldy peanuts was higher than that of stained peanut kernels.

The efficacy of local steroid injection on the extravasation of vesicant anticancer drugs is controversial. In this study, the efficacy of local steroid injection was evaluated macroscopically and histologically in the extravasation models of doxorubicin (DXR), vinorelbine (VNR), and paclitaxel (PTX)in rats. Macroscopically, gross skin lesions were reduced by local steroid injections in rats treated with DXR and VNR. PTX did not cause gross skin lesions in most rats regardless of local steroid injection. Histologically, however, DXR, VNR, and PTX all induced deep tissue lesions such as edema, inflammation, and necrosis. Therefore, the effect of local steroid injection seemed to be minimal. In particular, DXR induced extensive necrosis in the subcutaneous and muscle tissues. VNR-induced skin lesions were milder than those induced by DXR, but had full thickness. Lesions caused by PTX were the mildest. These findings suggest that although local steroid injections could serve a primary role in diluting anticancer drugs and reducing gross skin lesions by their anti-inflammatory effect, they have less ability for suppressing deep-tissue lesions developing over time.

Peptide amphiphile molecules (PA) are remarkably versatile and useful as building blocks for construction of complex supramolecular structures in a bottom-up fashion. Worm-like micelles of PA have been demonstrated to have successful application to creation of synthetic extracellular matrix materials for tissue engineering and regenerative medicine. However, the pathway of the self-assembly process of the PA worm-like micelle has not been fully characterized or understood. This work analyzes the self-assembly process leading to worm-like micelle formation in our designed PA with small-angle neutron scattering and atomic force microscopy. The experimental results demonstrate the existence of transient spherical micelles in the early stage of the process and subsequent micelle chain elongation by attachment of spherical micelles to the end of growing cylindrical micelles to form worm-like micelles in a process mimicking chain-growth polymerization.

Probiotic strains have been reported to have the ability to control allergic and inflammatory diseases. In this study, we studied the inhibitory effect of Bacillus subtilis (natto) (BS) on atopic dermatitis. The effects of continuous oral administration of BS for 4 weeks on the development of atopic dermatitis induced by Dermatophagoides farinae body antigen (DF) in NC/Nga (NC) mice were evaluated using 4 groups of mice: group (Gp) DF, DF(+) with no administration of bacteria (n=3); Gp DF/BS, DF(+) and BS(+) (n=5); and Gp PBS, DF(-) with no administration of bacteria (n=3). The mice were gavaged with 1.2 × 10(17) CFU/head of BS 6 times a week for 4 weeks, and DF was applied twice a week for 4 weeks. Histopathological examination revealed significant differences in auricular thickness between Gp DF (664.4 µm, SD=78.0) and Gp DF/BS (278.7 µm, SD = 88.8; p

乳腺腺腫は若年女性にみられるまれな腫瘍で, 管状腺腫 (tubular adenoma) と授乳性腺腫 (lactating adenoma) に亜分類される. 今回われわれは, 一部に線維腺腫様結節病変を伴った管状腺腫の1例を経験したので報告する.患者は23歳, 女性. 穿刺吸引細胞診および捺印細胞診で, 上皮細胞は管状, 腺房状ないし, シート状の結合の強い細胞集団であった. 細胞は中等大, 均一で大小不同はほとんど認めない. 核は円形～類円形. クロマチンは微細顆粒状で, 小型核小体が1～2個認められた. 背景には裸核状の間質細胞および筋上皮細胞がみられ, 線維腺腫 (丘broadenoma) を考える細胞像であった. 組織学的には管状腺腫と診断されたが, 内部に硝子化した線維性の小結節状病変が混在しており, その発生に関し線維腺腫との異同が問題となるものであった.

SPIE BiOS, 2008, San Jose, California, United States, Wataru Watanabe, Tomoko Shimada, Sachihiro Matsunaga, Daisuke Kurihara, Shin-ichi Arimura, Nobuhiro Tsutsumi, Kiichi Fukui, Kazuyoshi Itoh, "Selective labeling of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein," Proc. SPIE 6860, Multiphoton Microscopy in the Biomedical Sciences VIII, 68601B (15 February 2008); https://doi.org/10.1117/12.768745., We present space-selective labeling of organelles by using two-photon conversion of a photoconvertible fluorescent protein with near-infrared femtosecond laser pulses. Two-photon excitation of photoconvertible fluorescent-protein, Kaede, enables space-selective labeling of organelles. We alter the fluorescence of target mitochondria in a tobacco BY-2 cell from green to red by focusing femtosecond laser pulses with a wavelength of 750 nm.

1. The time courses of the relaxation, induced by removal of extracellular Ca2+, of K-depolarized mesenteric artery preparations from stroke prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY) were compared. 2. The time course of the decline in extracellular Ca2+ was estimated from the time course of the relaxation and the concentration-response curve of K+-depolarized preparations to Ca2+. The time course of the decline in the intracellular free Ca2+ concentration was also estimated from the reported relation between Ca2+ concentration and the contraction of skinned vascular smooth muscle. 3. The time course of relaxation was exponential, the curve being made up of three components. The time course was slower in preparations from SHRSP, especially the first component of the relaxation curve. 4. The time courses of the decline in the intracellular and extracellular Ca2+ concentrations were also exponential, being made up of three components and were also slower in the preparation made from SHRSP. 5. The wall and muscle layer of the mesenteric arteries used in the present experiments were significantly thicker in the SHRSP preparations. 6. Calculation of the half relaxation time, based on the diffusion of Ca2+ across the blood vessel wall, suggested that the slower relaxation in preparations from SHRSP is due largely to the thicker muscle layer, although differences in Ca2+ sequestration by the smooth muscle cells may also be involved.

European Conferences on Biomedical Optics 2005, 2005, Munich, Germany, Wataru Watanabe, Tomoko Shimada, Kazuyoshi Itoh, Sachihiro Matsunaga, Kiichi Fukui, "Femtosecond laser manipulation of subcellular organelles in living cells," Proc. SPIE 5863, Therapeutic Laser Applications and Laser-Tissue Interactions II, 58630B (26 August 2005); https://doi.org/10.1117/12.633079., Manipulation—that is, inactivation and movement—of subcellular organelles in living cells is important to understand cell dynamics. We review disruption of subcellular organelles in living cells by tightly focusing femtosecond laser pulses inside the cells. Photodisruption of organelles in living cells was experimentally confirmed by restaining of organelles. Femtosecond laser based nanosurgery has the possibility to remove or manipulate organelles in living cells and may lead to elucidation of functional interactions between organelles, protein transportation, and inter-cell communication.

The synthesis of zeolitic imidazolate framework-8 (ZIF-8) films in an aqueous system was achieved. ZIF-8 films with controllable thickness were successfully grown on a modified substrate at room temperature. The 3-(2-imidazolin-1-yl)propyltriethoxysilane (IPTES) was used to first form a pseudo-surface of ZIF-8 on a glass substrate, followed by layer-by-layer growth. The film thickness of ZIF-8 was controlled within the range from 220 to 640 nm per growth cycle by changing the reactivity of the zinc source. Notably, the use of a preorganized zinc source led to drastic changes in the formation rate of ZIF-8. The use of a low-reactivity growth solution containing zinc acetate thus allowed the preparation of dense ZIF-8 films.

Peptide amphiphiles (PA) can self-assemble into both spherical micelles and worm-like micelles. The control of worm-like micelle formation of PA is an area of active research, most often accomplished by modulating the temperature, salt content, or pH of the environment. In this work, we demonstrate the shear-induced formation of worm-like micelles in our designed peptide amphiphile C16-W3K. Before adding shear, the peptide amphiphiles form spherical micelles in solution and exhibit little to no viscoelasticity. As the solution is subjected to simple shear flow, with increasing shear rate, spherical micelles form rapidly into elongated worm-like micelles up to microns in length. Though it has been reported that some dilute surfactant solutions exhibit shear-induced increase in viscosity due to a shear-induced structural transition, unlike this class of surfactants, the PA micelles change their structures from sphere to worm-like irreversibly and the resultant worm-like micelles are highly stable due to the β-sheet formation, i.e. intermolecular hydrogen bonding, in their peptide regions. In our PA system, shear force induced the change not only of the micelle structure but also of the peptide secondary structure simultaneously. Such hierarchical transitions caused by simple shear make this PA system useful for application as an injectable tissue engineering matrix.

Spatial and temporal information about intracellular objects and their dynamics within a living cell are essential for dynamic analysis of such objects in cell biology. A specific intracellular object can be discriminated by photoactivatable fluorescent proteins that exhibit pronounced light-induced spectral changes. Here, we report on selective labeling and tracking of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein with near-infrared femtosecond laser pulses. We performed selective labeling of a single mitochondrion in a living tobacco BY-2 cell using two-photon photoconversion of Kaede. Using this technique, we demonstrated that, in plants, the directed movement of individual mitochondria along the cytoskeletons was mediated by actin filaments, whereas microtubules were not required for the movement of mitochondria. This single-organelle labeling technique enabled us to track the dynamics of a single organelle, revealing the mechanisms involved in organelle dynamics. The technique has potential application in direct tracking of selective cellular and intracellular structures.

Lasers and Applications in Science and Engineering, 2006, San Jose, California, United States, Wataru Watanabe, Tomoko Shimada, Sachihiro Matsunaga, Hiroshi Ishii, Tsunehito Higashi, Kiichi Fukui, Kazuyoshi Itoh, "Nanosurgery of sub-cellular organelles in living cells using a femtosecond laser oscillator," Proc. SPIE 6108, Commercial and Biomedical Applications of Ultrafast Lasers VI, 610804 (28 February 2006); https://doi.org/10.1117/12.645474., Femtosecond laser pulses in the near-infrared region have potential applications in nanosurgery in cell biology. Femtosecond laser pulses can be used to selectively disrupt and dissect intracellular organelles in living cells. We report on disruption of fluorescence-labeled nucleus and mitochondria in living HeLa cells using a femtosecond Ti:sapphire laser oscillator with a repetition rate of 76 MHz. We examined the effectiveness of the restaining method in combination with fluorescence recovery after photobleaching (FRAP) analysis to discern disruption or bleaching.

Shimada T., Watanabe W., Matsunaga S., et al. Intracellular disruption of mitochondria in a living HeLa cell with a 76-MHz femtosecond laser oscillator. Optics Express, 13, 24, 9869. https://doi.org/10.1364/OPEX.13.009869., Femtosecond laser pulses can be used to selectively disrupt and dissect intracellular organelles. We report on disruption of mitochondria in living HeLa cells using a femtosecond laser oscillator with a repetition rate of 76 MHz. We studied the laser parameters used for disruption. The longterm viability of the cells after disruption of a single mitochondrion was confirmed by the observation of cell division, indicating that intracellular disruption of organelles using a femtosecond laser oscillator can be performed without compromising the long-term cell viability.

The efficacy of typical sorting methods which have been practically employed in industry for excluding aflatoxin-contaminated materials from peanuts was evaluated by determining aflatoxin concentration in the peanuts before and after sorting treatments. The efficacy of aflatoxin removal from panuets varied from almost 0 to 100% depending on the methods used.The aflatoxin concentration in peanuts was most effectively reduced by the manual exclusion of deteriorated peanuts, such as moldy or worm-eaten nuts, based on visual inspection. The effective removal of aflatoxin by using a color sorter required precise tuning of the operating conditions. Sifting and air-fan sorting had no significant effect.In some cases, these sorting procedures, even in combined use, could not reduce the aflatoxin concentration in peanuts to below 10ppb, which is the legal concentration limit under Japanese customs regulations.