The short version of chronic hepatitis B fits in a sentence. The long version — which is the one that helps — is below.
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市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
increase activity against the chosen target reduce activity against unrelated targets improve the druglikeness or ADME properties of the molecule. This process will require several iterative screening runs, during which, it is hoped, the properties of the new molecular entities will improve, and allow the favoured compounds to go forward to in vitro and in vivo testing for activity in the disease model of choice. Amongst the physicochemical properties associated with drug absorption include ionization (pKa), and solubility; permeability can be determined by PAMPA and Caco-2. PAMPA is attractive as an early screen due to the low consumption of drug and the low cost compared to tests such as Caco-2, gastrointestinal tract (GIT) and Blood–brain barrier (BBB) with which there is a high correlation. A range of parameters can be used to assess the quality of a compound, or a series of compounds, as proposed in the Lipinski's Rule of Five. Such parameters include calculated properties such as cLogP to estimate lipophilicity, molecular weight, polar surface area and measured properties, such as potency, in-vitro measurement of enzymatic clearance etc. Some descriptors such as ligand efficiency (LE) and lipophilic efficiency (LiPE) combine such parameters to assess druglikeness. While HTS is a commonly used method for novel drug discovery, it is not the only method. It is often possible to start from a molecule which already has some of the desired properties.
where E is the electric field strength, B is the magnetic field induction, q is the charge of the particle, v is its current velocity (expressed as a vector), and × is the cross product. So the force on an ion in a linear homogenous electric field (an electric sector) is:
=== Films and television === Chains (film), a 1949 Italian melodrama film Chains (Blackadder), a 1986 episode of the British sitcom Blackadder II Chain (advertisement), a 1994 television advertisement for Guinness Chains of Love (TV series), a 2001 American dating game show adapted from a Dutch television series Chain (film), a 2004 film written and directed by Jem Cohen Chains, a 2009 short film starring TNA wrestler Kurt Angle
Canned goods and canning supplies tend to sell well during economic recessions as financially stressed consumers engage in cocooning, a behavior in which people stay home and reduce discretionary spending such as dining out and entertainment . Also, some people may become preppers and proceed to stockpile canned food. In February 2009 during a recession, the United States saw an 11.5% rise in sales of canning-related items. Some communities in the US have county canning centers which are available for teaching canning, or shared community kitchens which can be rented for canning one's own foods.
Sources: en.wikipedia.org
=== Non-substrate-like inhibitors === Non-substrate-like inhibitors do not take after dipeptidic nature of DPP-4 substrates. They are non-covalent inhibitors and usually have an aromatic ring that occupies the S1-pocket, instead of the proline mimetic. In 1999, Merck started a drug development program on DPP-4 inhibitors. When they started internal screening and medicinal chemistry program, two DPP-4 inhibitors were already in clinical trials, isoleucyl thiazolidide (P32/38) and NVP-DPP728 from Novartis. Merck in-licensed L-threo-isoleucyl thiazolidide and its allo stereoisomer. In animal studies, they found that both isomers had similar affinity for DPP-4, similar in vivo efficacy, similar pharmacokinetic and metabolic profiles. Nevertheless, the allo isomer was 10-fold more toxic. The researchers found out that this difference in toxicity was due to the allo isomer's greater inhibition of DPP-8 and DPP-9 but not because of selective DPP-4 inhibition. More research also supported that DPP-4 inhibition would not cause compromised immune function. Once this link between affinity for DPP-8/DPP-9 and toxicity was discovered, Merck decided on identifying an inhibitor with more than a thousandfold affinity for DPP-4 over the other dipeptidases. For this purpose, they used positional scanning libraries.
=== Lesbian culture === Violets became symbolically associated with romantic love between women. This connection originates from fragments of a poem by Sappho about a lost love, in which she describes her as "Close by my side you put around yourself [many wreaths] of violets and roses." In another poem, Sappho describes her lost love as wearing "violet tiaras, braided rosebuds, dill and crocus twined around her neck". In 1926, one of the first plays to involve a lesbian relationship, La Prisonnière by Édouard Bourdet, used a bouquet of violets to signify lesbian love.
== Computational challenges == The sequencing technologies described here produce raw data that needs to be assembled into longer sequences such as complete genomes (sequence assembly). There are many computational challenges to achieve this, such as the evaluation of the raw sequence data which is done by programs and algorithms such as Phred and Phrap. Other challenges have to deal with repetitive sequences that often prevent complete genome assemblies because they occur in many places of the genome. As a consequence, many sequences may not be assigned to particular chromosomes. The production of raw sequence data is only the beginning of its detailed bioinformatical analysis. Yet new methods for sequencing and correcting sequencing errors were developed.
==== Reaction with protein amino groups ==== Hypochlorous acid reacts readily with amino acids that have amino group side-chains, with the chlorine from HClO displacing a hydrogen, resulting in an organic chloramine. Chlorinated amino acids rapidly decompose, but protein chloramines are longer-lived and retain some oxidative capacity. Thomas et al. concluded from their results that most organic chloramines decayed by internal rearrangement and that fewer available NH2 groups promoted attack on the peptide bond, resulting in cleavage of the protein. McKenna and Davies found that 10 mM or greater HClO is necessary to fragment proteins in vivo. Consistent with these results, it was later proposed that the chloramine undergoes a molecular rearrangement, releasing HCl and ammonia to form an aldehyde. The aldehyde group can further react with another amino group to form a Schiff base, causing cross-linking and aggregation of proteins.
The RCC's early economic policy has been characterized as being state capitalist in orientation. Many initiatives were established to aid entrepreneurs and develop a Libyan bourgeoisie. Seeking to expand cultivatable acreage, in September 1969 the government launched a "Green Revolution" to increase agricultural productivity and lessen Libyan reliance on imported food. They hoped to make Libya self-sufficient in food production. All land expropriated from Italian settlers or unused was repossessed and redistributed. Irrigation systems were established along the northern coastline and various inland oases. Production costs often surpassed produce value, keeping production in deficit and relying on state subsidies. With crude oil as the country's primary export, Gaddafi sought to improve Libya's oil sector. In October 1969, he proclaimed the current trade terms unfair, benefiting foreign corporations more than the Libyan state, and threatened to decrease production. In December, Jalloud successfully increased the price of Libyan oil. In 1970, other OPEC states followed suit, leading to a global increase in the price of crude oil. The RCC followed with the Tripoli Agreement of 1971, in which they secured income tax, back-payments and better pricing from the oil corporations; these measures brought Libya an estimated $1 billion in additional revenues in its first year. Increasing state control over the oil sector, the RCC began a program of nationalization, starting with the expropriation of British Petroleum's share of the British Petroleum-N.B.
Sources: en.wikipedia.org
=== Ornamental uses === Rhodium finds use in jewelry and for decorations. It is electroplated on white gold and platinum to give it a reflective white surface at time of sale, after which the thin layer wears away with use. This is known as rhodium flashing in the jewelry business. It may also be used in coating sterling silver to protect against tarnish (silver sulfide, Ag2S, produced from atmospheric hydrogen sulfide, H2S). Solid (pure) rhodium jewelry is very rare, more because of the difficulty of fabrication (high melting point and poor malleability) than because of the high price. The high cost ensures that rhodium is typically applied as an electroplate. Rhodium has also been used for honors or to signify elite status, when more commonly used metals such as silver, gold or platinum were deemed insufficient. In 1979 the Guinness Book of World Records gave Paul McCartney a rhodium-plated disc for being history's all-time best-selling songwriter and recording artist and in 2008, Barack Obama gave his wife a rhodium ring.
for the 2D (linear) ion trap were also given in literature. There are at least two postulates about the nature of the DC component. The first, of which has been attributed to Ding, assumes for the DIT that the DC component, U depends on not only the mid-level of the AC voltages, V1and V2, but also the duty cycle, d of the waveform:
In 2015, they collaborated with the electronics company HTC to develop the HTC Vive, a virtual reality headset released in 2016. Valve's president, Gabe Newell, aimed for Valve to become more like Nintendo, which develops games in tandem with hardware, allowing them to create innovative games such as Super Mario 64 (1996). In 2016, Valve released The Lab, a collection of VR minigames, and recognized that many players wanted a more ambitious VR AAA game. Walker wondered if they could develop a VR "killer app" equivalent to the influential FPS Doom in 1993.
=== Peptide === Ghrelin (Lenomorelin, GHRL) GHRP-1 GHRP-2 (Pralmorelin; GHRP Kaken 100; GHRP-2; KP-102, GPA-748, WAY-GPA-748) GHRP-3 GHRP-4 GHRP-5 GHRP-6 (SKF-110679) Alexamorelin Examorelin (hexarelin; EP-23905, MF-6003) Ipamorelin (NNC 26-0161) Relamorelin (RM-131, BIM-28131, BIM-28163) Tabimorelin (NN-703)
Legendre did an impressive amount of work on elliptic functions, including the classification of elliptic integrals, but it took Abel's study of the inverses of Jacobi's functions to solve the problem completely. He is known for the Legendre transformation, which is used to go from the Lagrangian to the Hamiltonian formulation of classical mechanics. In thermodynamics it is also used to obtain the enthalpy and the Helmholtz and Gibbs (free) energies from the internal energy. He is also the namesake of the Legendre polynomials, solutions to Legendre's differential equation, which occur frequently in physics and engineering applications, such as electrostatics. Legendre is best known as the author of Éléments de géométrie, which was published in 1794 and was the leading elementary text on the topic for around 100 years. This text greatly rearranged and simplified many of the propositions from Euclid's Elements to create a more effective textbook.
Sources: en.wikipedia.org
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.