CINXE.COM
Just a moment...
<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "www.cell.com",cType: 'managed',cRay: '914a44cdca75f8ec',cH: '2SFatDDhvtM5rxLSDQoBdlKI.TN3dKTPEGzXM1U2RQk-1740010175-1.2.1.1-9IqMiGRCci4.LQPIRn.RHEo3w12sCbcqaczVEgUchgGbprFQVlVOL13DlEZiPlJc',cUPMDTk: "\/article\/S1550413111004682\/pdf?__cf_chl_tk=TSccAJxXqGRJBNhXy4rnGUJWrjoEgmh5zwuLG54sTsg-1740010175-1.0.1.1-OG0xgvB77xAj8ozukpO3S06ddmJAoocR5PeLSF0_vP8",cFPWv: 'g',cITimeS: '1740010175',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported-browser",fa: "\/article\/S1550413111004682\/pdf?__cf_chl_f_tk=TSccAJxXqGRJBNhXy4rnGUJWrjoEgmh5zwuLG54sTsg-1740010175-1.0.1.1-OG0xgvB77xAj8ozukpO3S06ddmJAoocR5PeLSF0_vP8",md: "lRx_WmOFkuhJX1.5fmC1SoAampSUUzQIVXgiykE8Xa4-1740010175-1.2.1.1-iyNG7XFH5il33LR.upD0OpdVpc51uhltQRTunHph7.UdWjltCJTzApn8p5Uexn8MOCw74CdomLOd0VUsyC2m0OlotVKHD5QnJKNIVlFhFEnSOWGK_x4ii1RhjCxaQQellUYI0B_22a5Uw2lZrYTZPnlB.t5V7r0uTzalhbHAlcamqA0tadU5PMBVfC_RaF3qokXW5kIKjBzEDZt6EJ.JFvE4SMY_icPu8e8JzEYy4AFbpnZZ6iRbL._SKqF7ohskUoelrVzF7iEmD1dVipmGMscSr2T1BXDj2hwzdnbZf_V1__5nrD3pKlLyRGjVsONnq_6eo3RDwvqSNR3xUMezegRw5v9vCK5KXapGWSRxr0gxU6OOnK9iklMuKz1F4XdG.Zd0M2NZbEQEq9oPYsq.kd1NBq9pUac3hwX2yDRrC5agjN6w8.uIIawnmZg_GCB5D.UpwSvpCYxnYPjIZiiWgcIwPeKp2fGJOQhleHSi_IrxS19KV2zQ_4jQl4oxw2I45CvnfklkES4rBfxbto36wUIHRtwBehEjaRCaLllRfMuNXAFQ6SalrAZXUf_wRflDI_brka0akx_qr6YYdMVp_AFAr7BKEnIxj5R9NyEuww2V7ERPR3uzWO15_r_.5nBohFX90opPvqzdmudnJ76JQ1Gg8d6xgzJKqqkGZLvzSKiL145FEPFcIZIbUijtAC1cfrTxbrLd2YNd0VUkpT5PmvAWty7US1HxbYS7DmEWqBxeYoBKNbhtELV8FS6oM12gRjA3AxaF1w2dHNjjFFx4AJSQULCxIZLGN6f1xoVYFFlme7ZpjQHf1F.lH5CUeEi2WfL6FZRYxTqZUta_t3DJMSXP4m2NF0XVq06XYJCM_E9CWtmOyOVcC9jtu_pR2pRQo1HbaeNm6UK_gHZVrnc_aycFwiU.TMlIEDe.gjFBDVEm8h4BjBj9nNcEa7IhKQea3PgXLIG2ORPMC933ULGZOKEMvkUUZ9v4_BNDijYWu5XtfIMr8UvJZtPQxmxSgEAtjAQS7joP3nAMe7DtO.6PHi_PKjpIMBMSKbcdviOHMRBTy80BrOfEvzpT9lkCM8nqHjYCRsLbEbRw6geON6lO4eb9.S_r7I9v7aG7RS2Pu7dYK.u5F3ivAGqG4t.pQe1VkaIgaOKH.uQES8VHSiM2GwqDI451peXzZEVSUlq.HzpkZ0zHLb0_r6xFcBn2s5L52R.ndkACXuPeUw5OEXHM2F7Sbs8fxiKaojaPsuMEeKZDhgZpHWi_iCevwPmjG6k7K661WCzhOJZL38c1tuCz5kVEJXG7QlizMCdWPVOV2B7NeY_Ugbv.YbmUEbA1gQ.P65uqJU1FoSPqTPjiyesLraXtfhJ.KqYnPhzRrxm_b6k7eoFTvQTu8ojJzdtymcy_V0WccFm7UTIeMJZ..ufomB4cToEQXJJLMmv2HX1rGy9ozm1kqei67g6xiiJ_Np1A0HnE0J92voraNyA1D0aJVh1Vlooq7tauJXboXTqEh4OdPtzdLt0E2YM.37XJlhIkonoONeliH6TWFKTmPefYtCohhABuVNMzwEKJWBh.kbYrzLxTM1.C6Vc5Giv.dhTZbodwBVg.o7v.6N7kFWpA7MDmJDzTOL5.xo651UO2y9kcCwq9WT_2a0xHDn_6K0_osFSS7z2xFPZthEe2qAHaBjreR94O7ub0hq.bAtM9fkPq0ydCdih5Vt.nvCE2l8kI95Zovcu9MT0ETuOYclqThe1AkGD9ECd6kAcbofTHSaP8M3uARnAQzArmyqoT7TQ.vNydNamuJuKudeOlvsmfH_h0idSrd4DholluMM5TQFv3ac4rMzFIPxuNsgFNAcEJUXt0unwVOuGG8lpF7tMrbWV7fB_Dl0Y.M0zDEBEHsVIH2anaKk23IO2YukOlRFmZTkVgbP9g8Rfc91fjGC_Y0a0.LEbMcJrdhu12L4uYMKbbz8E_pBCpP59tFxvA8flIZ4IR0t60JKsA1B2Ek3cSGuo57WmtqslWmjeLJTO.tPMcuetzA91iqq.El.dvD8tji8qVHdCy1XVJK0R4KgoM3HZvg7MObXuRdQUXXXMStE6tJH2QvA7W._489frjLoSTi19LRqyuBZeIi_VnRVb1xec6d1bMfzDo1QYhuuts.Z5BqMqX60fi3r2tXEfZpQ4LMypocRytJAXVR3gtSMLiTj_we1_MP5EI7IRySv10rx6WmlhmXt0APWjOEDoUwqMEVOxXq0nbm7RnEa2JVEn_xQVrcRoWEfeOk2Jp5qSfc.2HYFBzcOT8Q5gXm6b8w3g7FRcSs1jWmsCvmJaorQWzA8K.578.N6wHk_fQh3eosWYUWgID8vl4mKQOUo5UG9wy9BHJVbJAD1s2YIshH6Em5OxT4s4JdChhj_iNjNYvI8vHJh4zSFjVWxP4Gqnv5Udt7DIM7ptn7qJ_Xb7Y0XnoehdnfE6ID6Z0TJ5Fz7913NrofT6g17OMIuQTT1WoMPADN1qidbfAj7EeNhFhtdPdXOC964FpmaGQi1ZK8mv2UKulvlI.LZOo226NNM2rciLuQ49hCZuhR7X9qDj8BYjqAw",mdrd: "1iiA8EAXIj4iQ8FQmoPufszs_BMIcH8QajQa2pwcyUM-1740010175-1.2.1.1-10.ri8xDs7RsMNa5ymToxQ7s.ZoYPHWz03VDy5V8jvYQWNuQg8CnM6ni4s14MSGTVYEl.35u8Y1zVtJs4fVyZcsQLsQxe6iDPX8rvXYFEuElmhb6F788zeJ6NSVm8mx_3itGzso__E5FbTspd7iEkJqVB_hqqQ1yayctEhU63Fnp3C121wm_cfrJClFWFwIH5dgn8CbYrPUhUCNA5lpSOzYoiR7SZd3kVGTRn_k2gPYH_DCQevkj.2v4iUqjg0MMllkzJjdbdZwjB5lrBNHAYVNbQOJvDxB5Bv01goaqEPCxl8GspGXbvywnqDfTTYjrtFU1hj8__PvVX4DRtECdA.PIfk3ed5cmu0RLCeJgXEygjr5CRc162MBbRWm3cV956Ly7sKGMbhV0n7E3QsUVg0_IeZiBOPYg1iLyEmSQ_kb..AMxW0B_UMPhruDEx6f_7AmZ9nruitMetoaJrndeB2XLogzYT8fhKZaA_Vpu7cidXtMLSmKFNAtI.UZ6JHToGPn67z7YDFSr2Ru2aUdvPeegfAH38skaC0op8piGW8xnDuf0OO5YT7bxducmPc3ktBfAkofg_TLud4fEiJTwvx9jSbefL6pff7NU0mFZ8y7wpbSpLAeTHeXO8HrS5jf.OP_HWPUqSQPEUG2.iYlNwcr_..fWSZOtaKIe8vaAdkmodKlddK2WEQbVOBP8tdnf0Uaie2MeEfA9cnryPnnkho0QddRM97Tdg1SURZYP0m0dxNyr1oFpZBbr2S9d7MFlqM.C0r43dhjGLlYNoxZ9QMUkfP1fp0jMBgtYBPULnqVCqz6HiMhYC9L9TGFlNcAlCrjSuBK_os2t9jLXgFnDnS8arj9pCRSVMO2o4VDH5I4OjgM9GFS.rXlvXa3lZlXdos.W9L.j.CiUprI2m47uexYLMGzkIiVDAOdcrGKTiWGRGanKMbegsQJT_lycF4itfSogCikHThkg27CFer0pb3ubLO8mRslxrBQ4aNHi6_TjBcd.8B4iUQvTEz8Ztzu_8i3RtJnbsM9eYU.Y1dJaE4G.1Pd2nGun6Rb5kzuyuRgL2vblAyNkPQd0AYVaH2.ifBsdyzPKE0gwa8e18kviXw0mnXrbdS8EbO.0Vs83dyyzS.sCC45yFcwQlHOGmIze.zvhl9DE0qG_kbjLT2AgxirbbJWhvz3FqJARRf4ZBkUoKeYjhjDmIRUrb8zFA8oL.aWBd99tuZgwxmq4zUdCf3cUdZBymHtMoSGUWrLazHQqS3ax6PQ1GseWfRNg__7vlcVy6VaqY9vbkdkRgEF84Qozq4mlN9b5lD2LXBhqRAvz6D7C.3vzcd6cy63zP7FqMR3zLB9GqdDzuSaZtDF8gfa0ze7ox9NvvmUbDLnibjI0MIeKDXSKqIal00Zr0TMCW0OPQqw2sFc0ESluVdQ4MmcNvrlSjCIgHEN7Cuex8CSH7JaOkpCyAHr8bDLOl2CIUqNMx2cgvQjLqBCG70j0.5GkyeBYqYwCAgna_rOpM4a2R9RvMdnbzdsO0zFgXs9w3U2CWDa3W.DE3mgrHcv3HJAwKBVKdP0x7DSnAddD0cF97qu6LTZ3jfs7woJ9YEk_Lcl_f0Bi59QB1ODJlQgYJGWWF0bBywfKDhVJRXKbh_mvcOw0QhVtCKZImiNxVcsFHzjJ.CLD_aLd_cM82.D_Kykv9oRfcAssHXKrYSO0QzLWnM36iM3W1e2iqWmkLpajelvG.qG2Bv_ifpC9gmwpZPmDFkKcX3EETf031UF4bviWHxUVId.aEulF28eG_lA4vvFRN7P_2RkhM5kusEghGYvxhKGT8nJiy44ygDZlKR2bp5hcnc.s2zXeah886HLLqKbEcUibYv1e.wtNchfARezS.PHWQya.E98gVlNerNSRxnqtvuf8npXVret2kStBts31tu7RwzxtqgVxJgmm6wC__UenouW9hF32_UvjCDc"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=914a44cdca75f8ec';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/article\/S1550413111004682\/pdf?__cf_chl_rt_tk=TSccAJxXqGRJBNhXy4rnGUJWrjoEgmh5zwuLG54sTsg-1740010175-1.0.1.1-OG0xgvB77xAj8ozukpO3S06ddmJAoocR5PeLSF0_vP8" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>