产品简要
公司名称 :
赛默飞世尔
其他品牌 :
NeoMarkers, Lab Vision, Endogen, Pierce, BioSource International, Zymed Laboratories, Caltag, Molecular Probes, Research Genetics, Life Technologies, Applied Biosystems, GIBCO BRL, ABgene, Dynal, Affinity BioReagents, Nunc, Invitrogen, NatuTec, Oxoid, Richard-Allan Scientific, Arcturus, Perseptive Biosystems, Proxeon, eBioscience
产品类型 :
抗体
产品名称 :
Bcl-2 Monoclonal Antibody (100/D5)
目录 :
MA5-11757
规格 :
500微升
价格 :
美国473
克隆性 :
单克隆
宿主 :
小鼠
共轭标签 :
未共轭
克隆名称 :
100/D5
反应物种 :
人类, 小鼠, 大鼠
应用 :
免疫印迹, 免疫组化, 免疫细胞化学, 流式细胞仪, 免疫组化-石蜡切片
更多信息或购买 :
文章摘录数: 70
出版应用/物种/样本/稀释参考文献
  • 免疫印迹; 小鼠; 1:1000; 图 4d
Cho J, Lee J, Kim H, Lee H, Fang Z, Kwon H, et al. Ethyl Acetate Fraction of Amomum villosum var. xanthioides Attenuates Hepatic Endoplasmic Reticulum Stress-Induced Non-Alcoholic Steatohepatitis via Improvement of Antioxidant Capacities. Antioxidants (Basel). 2021;10: pubmed 出版商
  • 流式细胞仪; 人类; 1:50; 图 2d
Pearce M, Gamble J, Kopparapu P, O Donnell E, Mueller M, Jang H, et al. Induction of apoptosis and suppression of tumor growth by Nur77-derived Bcl-2 converting peptide in chemoresistant lung cancer cells. Oncotarget. 2018;9:26072-26085 pubmed 出版商
  • 免疫组化-石蜡切片; 人类; 1:100; 图 1
Bozkurt K, Yalçın Y, ErdemoÄŸlu E, Tatar B, ErdemoÄŸlu E, Çerçi S, et al. The role of immunohistochemical adrenomedullin and Bcl-2 expression in development of type-1 endometrial adenocarcinoma: Adrenomedullin expression in endometrium. Pathol Res Pract. 2016;212:450-5 pubmed 出版商
  • 流式细胞仪; 人类; 图 1
  • 免疫印迹; 人类; 图 s1
Deisting W, Raum T, Kufer P, Baeuerle P, Münz M. Impact of Diverse Immune Evasion Mechanisms of Cancer Cells on T Cells Engaged by EpCAM/CD3-Bispecific Antibody Construct AMG 110. PLoS ONE. 2015;10:e0141669 pubmed 出版商
  • 免疫组化-石蜡切片; 人类; 1:50
Alikanoglu A, Yildirim M, Suren D, Tutus B, Kaya V, Topal C, et al. Expression of Cox-2 and Bcl-2 in Paget's disease of the breast. Asian Pac J Cancer Prev. 2015;16:1041-5 pubmed
  • 免疫组化-石蜡切片; 人类; 1:50
Gurzu S, Kádár Z, Sugimura H, Bara T, Hălmaciu I, Jung I. Gastric cancer in young vs old Romanian patients: immunoprofile with emphasis on maspin and mena protein reactivity. APMIS. 2015;123:223-33 pubmed 出版商
  • 免疫组化-石蜡切片; 人类; 1:50
Sezgin Alikanoglu A, Yildirim M, Suren D, Yildiz M, Kaya V, Donem Dilli U, et al. Expression of cyclooxygenase-2 and Bcl-2 in breast cancer and their relationship with triple-negative disease. J BUON. 2014;19:430-4 pubmed
  • 免疫组化; 人类; 1:150
Khandakar B, Mathur S, Kumar L, Kumar S, Datta Gupta S, Iyer V, et al. Tissue biomarkers in prognostication of serous ovarian cancer following neoadjuvant chemotherapy. Biomed Res Int. 2014;2014:401245 pubmed 出版商
  • 免疫组化-石蜡切片; 人类; 1:50
Baspinar S, Bircan S, Orhan H, Kapucuoglu N, Bozkurt K. The relation of beclin 1 and bcl-2 expressions in high grade prostatic intraepithelial neoplasia and prostate adenocarcinoma: a tissue microarray study. Pathol Res Pract. 2014;210:412-8 pubmed 出版商
  • 免疫组化; 人类
Akay O, Aras B, Isiksoy S, Toprak C, Mutlu F, Artan S, et al. BCL2, BCL6, IGH, TP53, and MYC protein expression and gene rearrangements as prognostic markers in diffuse large B-cell lymphoma: a study of 44 Turkish patients. Cancer Genet. 2014;207:87-93 pubmed 出版商
  • 免疫组化; 人类; 1:50
Ortiz Martínez F, Perez Balaguer A, Ciprián D, Andres L, Ponce J, Adrover E, et al. Association of increased osteopontin and splice variant-c mRNA expression with HER2 and triple-negative/basal-like breast carcinomas subtypes and recurrence. Hum Pathol. 2014;45:504-12 pubmed 出版商
  • 免疫组化; 人类; 1:50
Korkmaz D, Bastu E, Dural O, Yasa C, Yavuz E, Buyru F. Apoptosis through regulation of Bcl-2, Bax and Mcl-1 expressions in endometriotic cyst lesions and the endometrium of women with moderate to severe endometriosis. J Obstet Gynaecol. 2013;33:725-8 pubmed 出版商
  • 免疫组化; 人类; 1:100
Schneider S, Kloimstein P, Pammer J, Brannath W, Grasl M, Erovic B. New diagnostic markers in salivary gland tumors. Eur Arch Otorhinolaryngol. 2014;271:1999-2007 pubmed 出版商
  • 免疫印迹; 人类
Peng X, Li W, Yuan L, Mehta R, Kopelovich L, McCormick D. Inhibition of proliferation and induction of autophagy by atorvastatin in PC3 prostate cancer cells correlate with downregulation of Bcl2 and upregulation of miR-182 and p21. PLoS ONE. 2013;8:e70442 pubmed 出版商
  • 免疫组化; 大鼠
Bingül I, Başaran Küçükgergin C, Tekkesin M, Olgac V, Dogru Abbasoglu S, Uysal M. Effect of blueberry pretreatment on diethylnitrosamine-induced oxidative stress and liver injury in rats. Environ Toxicol Pharmacol. 2013;36:529-538 pubmed 出版商
  • 免疫印迹; 人类; 1:200
Karaayvaz M, Zhai H, Ju J. miR-129 promotes apoptosis and enhances chemosensitivity to 5-fluorouracil in colorectal cancer. Cell Death Dis. 2013;4:e659 pubmed 出版商
  • 免疫组化; 大鼠
Huniadi C, Pop O, Antal T, Stamatian F. The effects of ulipristal on Bax/Bcl-2, cytochrome c, Ki-67 and cyclooxygenase-2 expression in a rat model with surgically induced endometriosis. Eur J Obstet Gynecol Reprod Biol. 2013;169:360-5 pubmed 出版商
  • 免疫组化; 人类; 1:100
Ko E, Lee B, Kim Y, Lee E, Cho E, Han J, et al. Association of RASSF1A and p63 with poor recurrence-free survival in node-negative stage I-II non-small cell lung cancer. Clin Cancer Res. 2013;19:1204-12 pubmed 出版商
  • 免疫组化; 人类; 1:100
Erovic B, Kim D, Cassol C, Goldstein D, Irish J, Asa S, et al. Prognostic and predictive markers in medullary thyroid carcinoma. Endocr Pathol. 2012;23:232-42 pubmed 出版商
  • 免疫印迹; 人类
Zhang L, Ji Q, Ni Z, Sun J. Prohibitin induces apoptosis in BGC823 gastric cancer cells through the mitochondrial pathway. Asian Pac J Cancer Prev. 2012;13:3803-7 pubmed
  • 免疫组化; 人类; 1:100
Erovic B, Harris L, Jamali M, Goldstein D, Irish J, Asa S, et al. Biomarkers of parathyroid carcinoma. Endocr Pathol. 2012;23:221-31 pubmed 出版商
  • 免疫印迹; 大鼠
Jin X, Cao M, Zhou X, Yin H, Chen Z, Xu N, et al. Effect of different durations of overdistention on rat bladder function and morphology. Braz J Med Biol Res. 2012;45:921-8 pubmed
  • 免疫组化; 人类; 1:100
Erovic B, Al Habeeb A, Harris L, Goldstein D, Kim D, Ghazarian D, et al. Identification of novel target proteins in sebaceous gland carcinoma. Head Neck. 2013;35:642-8 pubmed 出版商
  • 免疫组化; 大鼠; 1:100
Baykara B, Micili S, Tugyan K, Tekmen I, Bagriyanik H, Sonmez U, et al. The protective effects of carnosine in alcohol-induced hepatic injury in rats. Toxicol Ind Health. 2014;30:25-32 pubmed 出版商
  • 免疫组化; 人类; 1:100
Cheng Y, Sheng W, Zhou X, Wang J. Pericardial synovial sarcoma, a potential for misdiagnosis: clinicopathologic and molecular cytogenetic analysis of three cases with literature review. Am J Clin Pathol. 2012;137:142-9 pubmed 出版商
  • 免疫组化; 人类
  • 免疫印迹; 人类
Youssef R, Hegazy R, Fawzy M, Abdel Halim D, Nabil N, Sayed S, et al. Peroxisome proliferator-activated receptor gamma, a possible culprit in mycosis fungoides: an immunohistochemical study. J Eur Acad Dermatol Venereol. 2012;26:1522-32 pubmed 出版商
  • 免疫组化; 人类
Bonzheim I, Salaverria I, Haake A, Gastl G, Adam P, Siebert R, et al. A unique case of follicular lymphoma provides insights to the clonal evolution from follicular lymphoma in situ to manifest follicular lymphoma. Blood. 2011;118:3442-4 pubmed 出版商
  • 免疫组化; 人类
Balta A, Filiz A, Kurt Y, Sucullu I, Yucel E, Akin M. Prognostic value of oncoprotein expressions in thyroid papillary carcinoma. Med Oncol. 2012;29:734-41 pubmed 出版商
  • 免疫组化; 人类
Arik D, Kulacoglu S. P53, bcl-2, and nm23 expressions in serous ovarian tumors: correlation with the clinical and histopathological parameters. Turk Patoloji Derg. 2011;27:38-45 pubmed
  • 免疫组化; 大鼠; 1:100
Oktem G, Uysal A, Oral O, Sezer E, Olukman M, Erol A, et al. Resveratrol attenuates doxorubicin-induced cellular damage by modulating nitric oxide and apoptosis. Exp Toxicol Pathol. 2012;64:471-9 pubmed 出版商
  • 免疫组化; 大鼠
Giris M, Erbil Y, Depboylu B, Mete O, Turkoglu U, Abbasoglu S, et al. Heme oxygenase-1 prevents hyperthyroidism induced hepatic damage via an antioxidant and antiapoptotic pathway. J Surg Res. 2010;164:266-75 pubmed 出版商
  • 免疫印迹; 人类
Singh B, Cook K, Vincent L, Hall C, Berry J, Multani A, et al. Cyclooxygenase-2 induces genomic instability, BCL2 expression, doxorubicin resistance, and altered cancer-initiating cell phenotype in MCF7 breast cancer cells. J Surg Res. 2008;147:240-6 pubmed 出版商
  • 免疫组化-石蜡切片; 人类; 1:50; 图 2B
Takei H, Buckleair L, Powell S. Immunohistochemical expression of apoptosis regulating proteins and sex hormone receptors in meningiomas. Neuropathology. 2008;28:62-8 pubmed
  • 免疫组化; 人类
Gurzu S, Jung J, Mezei T, Pávai Z. The correlation between the immunostains for p53 and Ki67 with bcl-2 expression and classical prognostic factors in colorectal carcinomas. Rom J Morphol Embryol. 2007;48:95-9 pubmed
  • 免疫组化; 人类; 1:100
Wang W, Bergh A, Damber J. Increased expression of CCAAT/enhancer-binding protein beta in proliferative inflammatory atrophy of the prostate: relation with the expression of COX-2, the androgen receptor, and presence of focal chronic inflammation. Prostate. 2007;67:1238-46 pubmed
  • 免疫组化; 人类; 1:100
Ma J, Shi Q, Zhou X, Meng K, Chen J, Huang W. Lymphoma-like lesion of the uterine cervix: report of 12 cases of a rare entity. Int J Gynecol Pathol. 2007;26:194-8 pubmed
  • 免疫组化; 人类; 1:100
Altaner S, Gucer F, Tokatli F, Guresci S, Ozdemir C, Puyan F, et al. Expression of Bcl-2 and Ki-67 in tamoxifen-associated endometrial polyps: comparison with postmenopausal polyps. Onkologie. 2006;29:376-80 pubmed
  • 免疫组化; 人类
Bulut S, Uslu H, Ozdemir B, Bulut O. Expression of caspase-3, p53 and Bcl-2 in generalized aggressive periodontitis. Head Face Med. 2006;2:17 pubmed
  • 免疫印迹; 人类
Skvortsov S, Skvortsova I, Sarg B, Loeffler Ragg J, Lindner H, Lukas P, et al. Irreversible pan-ErbB tyrosine kinase inhibitor CI-1033 induces caspase-independent apoptosis in colorectal cancer DiFi cell line. Apoptosis. 2005;10:1175-86 pubmed
  • 免疫组化; 人类; 1:50
Nix P, Cawkwell L, Patmore H, Greenman J, Stafford N. Bcl-2 expression predicts radiotherapy failure in laryngeal cancer. Br J Cancer. 2005;92:2185-9 pubmed
Wang J, Yao W, Li J, Zhang Q, Wei L. Identification of a novel circ_0001946/miR-1290/SOX6 ceRNA network in esophageal squamous cell cancer. Thorac Cancer. 2022;13:1299-1310 pubmed 出版商
Mou Y, Sun Q. The long non-coding RNA ASMTL-AS1 promotes hepatocellular carcinoma progression by sponging miR-1343-3p that suppresses LAMC1 (laminin subunit gamma 1). Bioengineered. 2022;13:746-758 pubmed 出版商
Liu Y, Yang Y, Zhang L, Lin J, Li B, Yang M, et al. LncRNA ASAP1-IT1 enhances cancer cell stemness via regulating miR-509-3p/YAP1 axis in NSCLC. Cancer Cell Int. 2021;21:572 pubmed 出版商
Xue W, Li Y, Zhang M. Pristimerin inhibits neuronal inflammation and protects cognitive function in mice with sepsis-induced brain injuries by regulating PI3K/Akt signalling. Pharm Biol. 2021;59:1351-1358 pubmed 出版商
Deng Q, Wu L, Li Y, Zou L. MYBL2 in synergy with CDC20 promotes the proliferation and inhibits apoptosis of gastric cancer cells. Adv Clin Exp Med. 2021;30:957-966 pubmed 出版商
Xu R, Zeng M, Wu Y, Wang S, Zhang B, Zhang J, et al. Acetone Extract of Cornus officinalis Leaves Exerts Anti-Melanoma Effects via Inhibiting STAT3 Signaling. Onco Targets Ther. 2021;14:3487-3501 pubmed 出版商
Wang B, Sun X, Huang K, Zhou L, Qiu Z. Long non-coding RNA TP73-AS1 promotes pancreatic cancer growth and metastasis through miRNA-128-3p/GOLM1 axis. World J Gastroenterol. 2021;27:1993-2014 pubmed 出版商
Wang J, Luo J, Wu X, Gao Z. Circular RNA_0000629 Suppresses Bladder Cancer Progression Mediating MicroRNA-1290/CDC73. Cancer Manag Res. 2021;13:2701-2715 pubmed 出版商
Zhang Q, Long J, Li N, Ma X, Zheng L. Circ_CLASP2 Regulates High Glucose-Induced Dysfunction of Human Endothelial Cells Through Targeting miR-140-5p/FBXW7 Axis. Front Pharmacol. 2021;12:594793 pubmed 出版商
Yu C, Tang W, Lu R, Tao Y, Ren T, Gao Y. Human Adipose-derived mesenchymal stem cells promote lymphocyte apoptosis and alleviate atherosclerosis via miR-125b-1-3p/BCL11B signal axis. Ann Palliat Med. 2021;10:2123-2133 pubmed 出版商
Olorundare O, Adeneye A, Akinsola A, Ajayi A, Agede O, Soyemi S, et al. Therapeutic Potentials of Selected Antihypertensive Agents and Their Fixed-Dose Combinations Against Trastuzumab-Mediated Cardiotoxicity. Front Pharmacol. 2020;11:610331 pubmed 出版商
Chen J, Xu Q, Zhang W, Zhen Y, Cheng F, Hua G, et al. MiR-203-3p inhibits the oxidative stress, inflammatory responses and apoptosis of mice podocytes induced by high glucose through regulating Sema3A expression. Open Life Sci. 2020;15:939-950 pubmed 出版商
Li S, Liu N, Piao J, Meng F, Li Y. CCNB1 Expedites the Progression of Cervical Squamous Cell Carcinoma via the Regulation by FOXM1. Onco Targets Ther. 2020;13:12383-12395 pubmed 出版商
Liang F, Fu X, Li Y, Han F. Desoxyrhapontigenin attenuates neuronal apoptosis in an isoflurane-induced neuronal injury model by modulating the TLR-4/cyclin B1/Sirt-1 pathway. AMB Express. 2020;10:175 pubmed 出版商
Ullah M, Liu D, Rai S, Razavi M, Concepcion W, Thakor A. Pulsed focused ultrasound enhances the therapeutic effect of mesenchymal stromal cell-derived extracellular vesicles in acute kidney injury. Stem Cell Res Ther. 2020;11:398 pubmed 出版商
Fu B, Xue W, Zhang H, Zhang R, Feldman K, Zhao Q, et al. MicroRNA-325-3p Facilitates Immune Escape of Mycobacterium tuberculosis through Targeting LNX1 via NEK6 Accumulation to Promote Anti-Apoptotic STAT3 Signaling. MBio. 2020;11: pubmed 出版商
Zhang Z, Yang N. MiR-33a-5p inhibits the growth and metastasis of melanoma cells by targeting SNAI2. Neoplasma. 2020;67:813-824 pubmed 出版商
Li J, Luo J, Zhang Y, Tang C, Wang J, Chen C. Silencing of soluble epoxide hydrolase 2 gene reduces H2O2-induced oxidative damage in rat intestinal epithelial IEC-6 cells via activating PI3K/Akt/GSK3β signaling pathway. Cytotechnology. 2020;72:23-36 pubmed 出版商
Gurbi B, Brauswetter D, Varga A, Gyulavári P, Pénzes K, Murányi J, et al. The Potential Impact of Connexin 43 Expression on Bcl-2 Protein Level and Taxane Sensitivity in Head and Neck Cancers-In Vitro Studies. Cancers (Basel). 2019;11: pubmed 出版商
Che S, Bie L, Li X, Qi H, Yu P, Zuo L. Parthenolide inhibits the proliferation and induces the apoptosis of human uveal melanoma cells. Int J Ophthalmol. 2019;12:1531-1538 pubmed 出版商
Sheikholeslami K, Ali Sher A, Lockman S, Kroft D, Ganjibakhsh M, Nejati Koshki K, et al. Simvastatin Induces Apoptosis in Medulloblastoma Brain Tumor Cells via Mevalonate Cascade Prenylation Substrates. Cancers (Basel). 2019;11: pubmed 出版商
Xu L, Lin X, Zheng Y, Zhou H. Silencing of heat shock protein 27 increases the radiosensitivity of non‑small cell lung carcinoma cells. Mol Med Rep. 2019;20:613-621 pubmed 出版商
Khayyat L, Essawy A, Sorour J, Soffar A. Sunset Yellow and Allura Red modulate Bcl2 and COX2 expression levels and confer oxidative stress-mediated renal and hepatic toxicity in male rats. Peerj. 2018;6:e5689 pubmed 出版商
Li Z, Jiang X, Chen P, Wu X, Duan A, Qin Y. Combined effects of octreotide and cisplatin on the proliferation of side population cells from anaplastic thyroid cancer cell lines. Oncol Lett. 2018;16:4033-4042 pubmed 出版商
Gao D, Zhang J, Bai L, Li F, Dong Y, Li Q. Melittin induces NSCLC apoptosis via inhibition of miR-183. Onco Targets Ther. 2018;11:4511-4523 pubmed 出版商
Görük N, Deveci E. Immunoexpression of vascular endothelial growth factor and B-cell lymphoma 2 in the uterine tissue of rats treated with melatonin in the estrus phase1. Acta Cir Bras. 2018;33:629-640 pubmed 出版商
Shen P, Chen J, Pan M. The protective effects of total paeony glycoside on ischemia/reperfusion injury in H9C2 cells via inhibition of the PI3K/Akt signaling pathway. Mol Med Rep. 2018;18:3332-3340 pubmed 出版商
Qian Y, Song J, Sun P, Yi R, Liu H, Feng X, et al. Lactobacillus casei Strain Shirota Enhances the In Vitro Antiproliferative Effect of Geniposide in Human Oral Squamous Carcinoma HSC-3 Cells. Molecules. 2018;23: pubmed 出版商
Vaccari M, Mattapallil J, Song K, Tsai W, Hryniewicz A, Venzon D, et al. Reduced protection from simian immunodeficiency virus SIVmac251 infection afforded by memory CD8+ T cells induced by vaccination during CD4+ T-cell deficiency. J Virol. 2008;82:9629-38 pubmed 出版商
Qiu L, Sinniah R, I Hong Hsu S. Downregulation of Bcl-2 by podocytes is associated with progressive glomerular injury and clinical indices of poor renal prognosis in human IgA nephropathy. J Am Soc Nephrol. 2004;15:79-90 pubmed
图像
图像 1 :
赛默飞世尔 MA5-11757 图像 1
Formalin-fixed, paraffin-embedded human tonsil stained with Bcl-2 antibody using peroxidase-conjugate and DAB chromogen. Note cytoplasmic and membrane staining of follicular cells and no staining of reactive cells in the germinal center.
图像 2 :
赛默飞世尔 MA5-11757 图像 2
产品信息
产品类型 :
抗体
产品名称 :
Bcl-2 Monoclonal Antibody (100/D5)
目录# :
MA5-11757
规格 :
500微升
定价 :
美国473
克隆性 :
单克隆
纯度 :
蛋白质G
宿主 :
小鼠
反应物种 :
人类, 小鼠
应用 :
Flow Cytometry: 0.5-1 µg/test, Immunocytochemistry: 1:10-1:100, Immunohistochemistry (Paraffin): 1:50, Western Blot: 1:50
物种 :
人类, 小鼠
克隆 :
100/D5
抗体亚型 :
IgG1, kappa
储存 :
4° C
描述 :
BCL-2 is a key regulator of apoptosis that functions to either inhibit or promote cell death. The BCL-2 family members are also characterized by dimerizing to further modulate apoptosis. Bag1, for example, has been found to form a heterodimer with BCL-2 resulting in the enhancement of the anti-apoptotic effect of BCL-2. Bax and Bak have been shown to play a critical role in cytochrome c release from mitochondria and thus initiate apoptosis. Bax exerts a pro-apoptotic rather than an anti-apoptotic effect on cells. Constitutive expression of BCL2, such as in the case of translocation of BCL2 to Ig heavy chain locus, is thought to be the cause of follicular lymphoma. In most follicular lymphomas, neoplastic germinal centers express high levels of BCL-2 alpha protein, whereas the normal or hyperplastic germinal centers are negative. Two transcript variants of BCL-2, produced by alternate splicing, differ in their C-terminal ends. The overexpression of BCL-2 has been linked to human cancers such as B-cell lymphoma and prostate cancer.
免疫原 :
A synthetic peptide, aa 41-54 (GAAPAPGIFSSQPG-Cys) of human Bcl-2 protein
格式 :
液体
应用w/稀释 :
Flow Cytometry: 0.5-1 µg/test, Immunocytochemistry: 1:10-1:100, Immunohistochemistry (Paraffin): 1:50, Western Blot: 1:50
别名 :
apoptosis regulator Bcl-2; AW986256; B cell leukemia/lymphoma 2; B cell lymphoma 2 associated oncogene; B-cell CLL/lymphoma 2; B-cell leukemia/lymphoma 2; Bcl 2; BCL2; bcl-2; BCL2 apoptosis regulator; Bcl-2 protein; BCL2, apoptosis regulator; Bcl2-like protein; C430015F12Rik; D630044D05Rik; D830018M01Rik; OTTHUMP00000163680; PPP1R50; protein phosphatase 1, regulatory subunit 50
更多信息或购买 :
公司信息
赛默飞世尔
上海浦东新金桥路27号7号楼
analyze.cn@thermofisher.com
http://www.thermo.com.cn
1084193588
公司总部: 美国