AbstractPremiseDuring the COVID‐19 pandemic lockdown, all laboratory work was suspended, and we were obliged to work from home, causing delays in our research. As the disruption to supply chains made it difficult to obtain our regular lab supplies, we were obliged to search for substitutes. We became familiar with a plastic material known as biaxially oriented polypropylene (BOPP) that is widely used in the food industry for wrapping or storing fruits, vegetables, and meat. BOPP is easily dissolved in organic solvents such as xylenes, acetone, or thinner, but these reagents are very toxic, flammable, and can cause nausea in some users. After testing several alternatives, we found a polyurethane remover that proved to be an effective and relatively harmless BOPP solvent.Methods and ResultsBy dissolving thin slices of BOPP in a polyurethane solvent, we obtained a clean fluid that we used to obtain leaf surface prints that could be mounted on microscope slides with a coverslip. This fluid produced excellent bark and wood sections and can be used to obtain wood or charcoal surface prints. Our attempts to use it as a mounting medium were unsuccessful.ConclusionsBOPP dissolved in a polyurethane remover is a handy, versatile resource for plant microtechniques. In addition to its economic advantages, it is useful in terms of reducing plastic pollution.

2023-10-01·Food Research International

Alternative flexible plastic packaging for instant coffees

Article

作者: Moreira, Christiane Quartaroli ; Massulo Souza, Raquel ; Vieira, Roniérik Pioli ; Alves, Rosa Maria Vercelino ; Coltro, Leda

Instant coffees are consumed worldwide and their packages must protect them mainly from moisture gain. Flexible packaging stand-up pouches made by PET/Al foil/LDPE are currently used but, the look for alternative materials is interesting to replace the aluminum foil with reducing costs and focusing on sustainability. Therefore, the aim of this study was to evaluate the quality loss of freeze-dried and spray-dried (agglomerated and powder) instant coffees during 365 days at 25 °C/75% RH, packaged in five plastic structures: PET (polyethylene terephthalate)/Al (aluminum) foil/LDPE (low density polyethylene), LDPE/HDPE (high density polyethylene)/LDPE, BOPP (biaxially oriented polypropylene)/BOPP met (metallized)/PP, PET/PET met/LDPE and PET/BOPP met/LDPE. The results were compared with the shelf-life estimated by modeling the moisture sorption isotherms of the products by mathematical models. Results indicated that the lower the barrier to water vapor of the packaging material, the greater the gains in moisture and water activity of the instant coffees and in addition to being thermally less stable. After 365 days of storage, the three soluble coffees still had acceptable characteristics in the five packaging structures, indicating that it is possible to replace the currently used laminate, which contains aluminum foil, with recyclable structures. However, the greatest stability for the coffees was obtained using the alternative structures: BOPP/BOPP met/PP and LDPE/HDPE/LDPE, a result that was in concordance with that obtained by mathematical modeling.

2018-05-03·The Journal of Physical Chemistry A3区 · 化学

Photoinduced Reactions of Benzophenone in Biaxially Oriented Polypropylene

3区 · 化学

Article

作者: Shatalova, Olga V. ; Khudyakov, Igor V. ; Krivandin, Aleksey V. ; Efremkin, Alexei F. ; Levin, Peter P. ; Lomakin, Sergei M.

The photoinduced reactions of benzophenone (B) in biaxially oriented polypropylene (BOPP) were studied with nanosecond laser photolysis (N₂ laser, λ337.1 nm). The first observed transient was a triplet state ³B*. Decay of ³B* led to formation of a radical pair (RP) of BH^• and R^•, where R^• is a radical formed by hydrogen abstraction from BOPP (RH) by ³B*. We studied BOPP after the preheating for a short time in a temperature range 298-423 K, which is essentially lower than its melting point of 453 K. All measurements with not-heated and with preheated (annealed) BOPP were made at 298 K. A radical pair (RP) apparently decays as a contact pair ³[BH^•, R^•] in nonheated BOPP. A critical phenomenon takes place: dissociation of RP with a formation of free radicals in the polymer bulk is observed at preheating temperature T_crit ≈ 403 K and at a higher T. The physical process of heating and cooling of BOPP apparently resulted in the restructuring of crystallites, their agglomeration, shrinking of the distribution of crystallites according to their sizes in BOPP. Overall BOPP becomes softer which manifests itself in the radical kinetics. The decay kinetics of ³B* and RP in the cage fits well the first-order law. Rate constants were obtained. Radicals BH^•, which exit into the polymer bulk at temperatures of preheating T ≥ 403 K, decay by cross-termination according to the second-order law. A relatively high rate constant ∼10⁸ M^-1·s^-1 for this reaction was obtained due to diffusion of BH^• enclosed in the soft amorphous phase of BOPP. Properties of BOPP containing B were studied with ESR, DSC, IR, and WAXD.

项与 Boronated porphyrin 相关的新闻（医药）

2024-08-10

·生物探索

Nature | 肝窦内皮细胞充当“免疫变阻器”抑制病毒特异性CD8+ T细胞活性

引言 CD8+T细胞是控制乙型肝炎病毒（HBV）感染并杀死受感染肝细胞的关键，在慢性感染过程中，这群细胞往往功能失调，但目前人们仍不清楚究竟是什么因素导致肝脏中病毒特异性CD8+ T细胞功能丧失。近日，来自德国慕尼黑工业大学的Percy A. Knolle团队在Nature杂志上发表了一篇题为A liver immune rheostat regulates CD8 T cell immunity in chronic HBV infection的文章，他们证明肝窦内皮细胞（LSEC）作为肝脏“免疫变阻器”，通过与HBV病毒特异性CD8+ T细胞建立密切而广泛的接触，增强T细胞中的腺苷酸环化酶-cAMP -PKA信号传导，使T细胞受体信号通路的关键信号激酶的磷酸化受到损害，因而导致其功能受到抑制。该团队利用亲肝重组腺病毒构建急性和慢性HBV感染小鼠模型，观察到HBV病毒特异性CD8+ T细胞在持续感染中丧失颗粒酶B（GzmB）表达及其细胞毒性效应功能。为定义与T细胞功能障碍相关的转录程序，他们对比了两种模型中CD8+ T细胞的RNA-seq数据，发现慢性感染模型的病毒特异性CD8+ T细胞中cAMP反应元件调节蛋白（CREM）和共抑制受体转录活性增加。通过对3名HBV慢性感染者体内抗原特异性CD8+ T细胞的分析进一步证实CREM转录活性增强与HBV持续感染的相关性。这些结果提示CREM本身可能介导CD8+ T细胞效应功能下降，于是该团队构建了T细胞选择性ICER表达丧失的Icerfl/fl×Cd4cre小鼠（ICER是CREM诱导的靶基因转录阻遏物），但并未在慢性感染HBV的小鼠中观察到感染肝细胞的清除，说明CREM活性增加本身并不是导致HBV特异性CD8+ T细胞在慢性肝脏感染中活性丧失的原因。为了找出原因，他们重新分析了持续感染期间CD8+ T细胞的转录特征，发现与TCR信号传导相关的基因下调，联系上述CREM表达增加的结果，他们重点关注cAMP信号传导，因为cAMP能通过激活PKA诱导CREM表达，且调节性CD4+ T细胞以cAMP依赖性方式抑制CD8+ T细胞【1, 2】。然而，CD4+ T细胞的消耗并不影响HBV感染结果【3】，于是他们进一步研究肝脏中是否有其他细胞来执行cAMP信号诱导的任务。结果显示病毒特异性CD8+ T细胞与肝窦内皮细胞（LSEC）存在非常密切且广泛的物理接触，与LSEC进行体外共培养后，CD8+ T细胞中pPKA水平增加，而GzmB表达下调。此外，他们将从小鼠体内分离出的功能性CD8+ T细胞暴露于毛喉素（能通过刺激腺苷酸环化酶增加cAMP水平【4】），这种处理从表型上复制了持续感染期间的CD8+ T细胞特征，如pPKA浓度增加、GzmB和细胞因子表达丧失等。图1. 慢性HBV感染期间CD8+ T细胞功能失调机制示意图(Credit: Nature) 了解决定慢性乙型肝炎中HBV特异性CD8+ T细胞效应功能丧失的分子机制对于开发更有效的免疫疗法非常重要。这项工作表明通过靶向抑制性腺苷酸环化酶-cAMP-PKA信号轴来调节肝脏免疫变阻器的功能，可能会提高慢性HBV感染中HBV特异性CD8+ T细胞活性。参考文献 1. Rauen, T., Hedrich, C. M., Tenbrock, K. & Tsokos, G. C. cAMP responsive element modulator: a critical regulator of cytokine production. Trends Mol. Med. 19, 262–269 (2013). 2. Bopp, T. et al. Cyclic adenosine monophosphate is a key component of regulatory T cell-mediated suppression. J. Exp. Med. 204, 1303–1310 (2007). 3. Stross, L. et al. Foxp3+ regulatory T cells protect the liver from immune damage and compromise virus control during acute experimental hepatitis B virus infection in mice.Hepatology 56, 873–883 (2012). 4. Seamon, K., Daly, J., Metzger, H., De Souza, N. & Reden, J. Structure–activity relationships for activation of adenylate cyclase by the diterpene forskolin and its derivatives. J. Med. Chem. 26, 436–439 (1983). https://doi-org.libproxy1.nus.edu.sg/10.1038/s41586-024-07630-7 责编|探索君排版|探索君文章来源|“BioArt” End 往期精选围观一文读透细胞死亡(Cell Death) | 24年Cell重磅综述（长文收藏版）热文 Cell | 是什么决定了细胞的大小？热文 Nature | 2024年值得关注的七项技术热文 Nature | 自身免疫性疾病能被治愈吗？科学家们终于看到了希望热文 CRISPR技术进化史 | 24年Cell综述

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100 项与 Boronated porphyrin 相关的药物交易

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适应症	最高研发状态	国家/地区	公司	日期
脑癌	临床2期	-	University of California	-
脑癌	临床2期	-	University of California	-
脑癌	临床2期	澳大利亚	Procept IP Pty Ltd.	-
脑癌	临床2期	-	Amorepacific Corp.	-
脑癌	临床2期	澳大利亚	Procept IP Pty Ltd.	-
脑癌	临床2期	-	Amorepacific Corp.	-
胶质瘤	临床2期	美国	Procept IP Pty Ltd.	-