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: "libraryhelp.ucsf.edu",cType: 'managed',cRay: '8e6e79b72f9b6020',cH: 'ocW6EJ3etd2PrFZRyz7U2CiuCLuXpaB4B6uvtOSHWtU-1732336766-1.2.1.1-N.MGdsT_uIuCyf.olIOCO8JbRv2c9nvbf2Yrb6AADBpRBgd6BUPiGQNNbU056YKm',cUPMDTk: "\/hc\/en-us?__cf_chl_tk=rCtoHGNUXNjLrg5hhLAt9j8gvCImC4KdU9aPlpi5zdM-1732336766-1.0.1.1-ysRQ3Mbo02ozb3Py3yaeI49wHFQciXUsIobIAagGsrY",cFPWv: 'g',cITimeS: '1732336766',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/hc\/en-us?__cf_chl_f_tk=rCtoHGNUXNjLrg5hhLAt9j8gvCImC4KdU9aPlpi5zdM-1732336766-1.0.1.1-ysRQ3Mbo02ozb3Py3yaeI49wHFQciXUsIobIAagGsrY",md: "McC7N5P8uijUWXVtfoT83a1UfaH4Dtn0Ryne7dgY3n4-1732336766-1.2.1.1-S22zvlTI8LYtFUe5ZmJpKKribI77gu197uZoZrWDKT2M.9IFzHd8r5t.UXWGd0IGoosKNKsjdsL.RPJiMJMwk8dsizlL2JdWfaemfe6RaUCKBoykhpyDVoBsTbz7t9Z4oexyyIzR8N7otGmJLq6k7JPVbvE4yIoP0g1t3YVEUsm7NwKV7V.NLqW1ekvI0ZAeJJOOa6YLSuqvtULFJNVChai1uc9nrbec2Ro__O.2oEuhMXBLX.JWrdNP4b0XZpH35En5DVI3Ivn58_QbNptWU2pxz1TUU_oZdERtHeqIlAAb6r0pcgWrIzkynfbwJav0lck3g17Xas9Gq65tdg8KNPHQroHda1N_nwAEtx2e8R4FdirUn6lf5NDc5pmwoZcW3SJqLrsgBY.MO_6b0kTwUStNke3vZPDcKZ5Jkumek6oeOxECO1XwFkxaJZedBqYU.3.qMzqTI9QCYNtvwUHJl3r6mLRfjvpfHRCSzlTlvssyXlZv37w2BmsgRUnQCrk.6ZRlQ26piuMIDE42ARWo6ZfAf4e4E7Qcxy05Ci86hxohZAvDQX_DDYLEKza4PAVsUmjHt7lW_QnSdCN_bpp9_aqsrsFFxLKq8ecLskttLhznEE7IKEDZC3fdS3w3cT3K2zYLPVUase1FOEcBfwG9uT0XwRlM6004W6.BA4cPwNr2os6uS8OF2oNpHPY0NTpCpH_OHbuipK9uVwiZigo7yfHgSVtgqlkLtbpP_tSHPGdy27v6gEkeOSiI4mgy0Dvyym2En7Dfl2itRcEIkesza6XltE0JVlfRzGJFa6WFO504H6cg5RjnC8Pi7xwQIT5oYHLbWsZmQxNLKgl2vvDRpeTVDCDuq4qyYb0k6VPyX5.__VCM7MSKWelLu5pzosupgJyCKPZ7xvIm1PHOUSCJHUgN7refMZMwpXjAV3qxnPKzAsygkjkDCcPbLsPcIMRvCHG_oKzaybEdSbk8FGXjKbVlD7lMzN2JNY0G5CUljboIn0TylIaUqvUUBFcQWjto4PjXg7KGIz.ivdmwwz3vrCLqp9vHpF4aSDddmpaVCaA4JdGNEhewMvqSvg1_LoH6h9oGfXRcafNakgbIIimI0qRaokEO3sYbt5YK8UdFBdv9dgldAG4Y.nY4zIE_6ruwO1UGREKlu.iKm0F8qpPfdE.PSnJ9rW9rFBA.k3bu7dHOo4DlD7eu1iBJmzakdiBxSUcK79tegxHAu6_5Ixusr.wCxp3CfuVfh7h9Qd_sUSld07T9.JhHO13ljUVv_RiirqEUVWaHV.xCFD6zV4V3m9totcTqX.9_ltAM8faTVN0kaX0oU9B45jqIacQZPo9Qlwk.zqiqBnEvFuI9idhRPIb3KFyOVCMvP1U845CDxmLoOl4dNCfPvCuWKi8Qub4eQFOFtJI8sZcUOR_Z6_rSyFtn._AVuk_rAZNxzxJoEcGd8coS0uy__zMt8Bmv37PDCNleuRA31FMwxXyDuPCL_1OeldH2uLyKD.g65HTUstipzM_N.45UTeg8KCNs2Hu9Ov7VmpVwhKe4m1Xl_6uOfY7WNO5lopcyrDZrn_d4kU8EwfbhoxZOow8pCm5CDdOX1Ni3a4mAR0jLuce2Wa3.BX1QqAriDzjiRx9YN_Z5ZyvicHzSPRjiOziGmzypz.pJCN2Vt39iVwfsiRizOwuqBPW9GovXL6cy0IcKH8etLoSpBIHeQH_8JGjCybv.YthiH4Gws.sCRCOd1cbvo4lAFOFmEMiJcpzBoRw2_SjdgahLIB_L68eoC5tMbW8gOzp1LO_XDhF46yKLNey2ntXrilSy7xDPWZZ4UHq7aJcduEt0rtvGMJtHubcyzwnXhc6f25h9Qku5mGk05xo_aEDtC_VImjf.6wfsHeUv5voz_XQvkuZePy8BoOne38ZEQl7mb8gq7y3wHKnYVVnh8iwBB7xWMgjCg8kcesoAMFEw.EevJuXjjDSs0Iz7nyFye.68NpKZqWP.cHjd84A6JaNX226DBsvPPpTj60DBkUK8FiiMX3wiNwNr32oIQZa1VjelBjJWrzGNfAEVGOEU31GB57WONCSHAT7_yduS0gaIQ7S9j708dk7nDvbbVURk8dW86DlXt9f5FlvEPC_hOyzu5S8vVXew8Yvr8Uritj8YWAh9vdOIK4UgR70jN9km.nuG1rtj.sJtWCtG_zOZNvTQ27xVdAbO894y2G7SIqDTj4IGXR4bM8gqHRlub8_SxHf6ouNaB.U5I9.c.f9pkiKTNIB8cTjQJDrwS8GTvZQCiYYZ98RGr1Xj9hx_RMQSGzRsVy4nx9oAr5dXcbrAZFBn660GC6mkq7FEPVPMuace1c2Wj6l00ZCuXOW88ds4KURihef3aYTM93V5slNCcjH1zWfPiJmh_.v8Esr6XNp6a7UKjtOr..L346ZuULu.DyoibAoBq3m.1mitXAUNjr.GGZ4fDaxhMBMT0kAEFHFVmKNqdx1vZtzfJo6.S6AydXV3ojikoQfWipO0vFvcZt3FL6OnXjFkOnMYQp5Sx4MyUWLhE2IgBH5I9jaRs3ry8jZ4TWkBxP9iy1LVNvSICPcDTPrt7GFXHyZ0smJGB_NhHmc6SEW1g7GqUwmsanuUQHOlna4h8t_Pl1j0pyoBpDTDcKhJ41QNCEWc3DFN5E6xZZVSPynhZjvR7HPZW7OmnwdHr3nYDihoXsA1OeQA_V7uDXmSlNmNSEUCq4uhk4iJMBfFmawcBeRU_CxVPLzR5QhDKh2a4RSYn7bXGowyzNwOqrzxiWsJNr8D0bGPBxNhxmWFRC7lw_Mg9VQ_aGtznovFSE8995S9YC02EtlOkdjkPcKGJm6OAcRjhqHRi0FR.YYTHAszKWBMrlEIaZbGlTBm_7xTixd3Hu8Sm9j6LbuYPJ0naAk8BpNhjLr4ZtKn43M",mdrd: "iuN5yBSoB_4hKb6wJ2O80KTbMXTVxGDsFOGYVY4gkqg-1732336766-1.2.1.1-04LCxruigPkKWpCF7WHZRoPPWlXjpAKjtzX88J7Gm6im8fImEVm5LrXNerqsOehRxFr.xwEgaq6XM6y461tl6vwpWPD8PnkEZmnhwKY9EIoPglFrDFdNKqee_igPekPbDPDhlnNGCH2fD0rqFaTuBWd_roRCfTruE3Gx9dy3WAmQGPmpjsPinyKYMnzkT7UZEwUqZ4gESs6nVki_Q2iQSYEJoRCv1l7.m4IZIiomWwXnj_7gZhMqU0LXmx3EFEHhOqsHIdlAYBT63Omh9KBNNkJXNa5A9hW1CG6jSAICvSVUm6fqRTHoISt2EV6dW18Hm1jn7zD4JSwxtV0.b61_rohpxTQWxdtEY4R5KgXq3QqNAU33Hh_uDNsIKVELSI8Ydw8.aC2jL7Qhq5HlCb06KyVa6P7bqOrT2zevf8k4vxvXf5t.7abtoTSYY5uv29aSZJw8Xuuqd4.OOv09uVC6djsOGfFtYXQfQ84UTUcjSWG.xffG1gw9yt3qxvUMyaRExqRbFExhVrIlNYQhVN3VumxgUfnc94LtmmkMllksqufH_kow87hygXUGjP6L5.5z5k2BM2RMmV1VD_1awXC35_n909ixkj0BLRjrtg94UdDHniFUH2JxjvUXXsf1nUQe6j8slefIMbQ5uveasThBrZNCps.U2a03A7LZsNCSHyRgzZW67Ubk66IwTIVk.gU2qH5_fj5sByE2qeOGvr.DdLQR6IuEAWLKDtZVnPZYbbM6xevyKIQ2Ubrat7yEJNcmVoEuvr7NzJ0MM6nYi5dduGBjlVMVZ0eAjMh7DoJhtoqaUyht4m5IJ1_o1nk7ns2zBkHn7wOvf2jnDjcwV24_pQnT.KUH8ygf166xpG9tA.KR..8zqr9TfORTGptWozVAycsBEnncrVkaWdL_eyS3n7EIjRblMBfBWmAU6HeUKneoZvlVKAmh3oR_fds8CJc0jGPTc5wShu3Vpha1JxmBSZtHWWS4p44QB.d3S1r599au_68Lsq4RNNP6RsBhmf6VMmNJVOcGv6O39t2ZfF80MP3BpOHyjLMnasox7Qtmh.300M9G9BvsUd92lNtPirlQfCnE9gb7ECewOl47S3qOwtG37ec3H0uSEHWDEmTJq6l9cmPM71e8JtUpQB33hi9_0NGLGOoWctvb63ZszCtJVbkeI7uUDCBmjcOpRgdWNJkMAhUL02LzY6ijTzsuTXbfCd.rzpz6iMnjhVZCIPZ07W_xSlLp3MHm7iHLGCSz85KyBO67uWdpWvKTMG8HxPxXZL0uDuHcPcdqEPpnzdZUlkPGJlcJmjkvVtmSO7MSHANYHoiwEpjn_hKdwWyrbFgdNeCL0N9Zwz1WKV.EKYuInIYSxPR0h.dtFXIrZJpzPXVPoqK8esval_OjQLfLZOhFFWzC_7EdF22CLl2n4WilNqTEWl5jXvh3.JGW4HZgir27HnYoU8AUswQGqPMV_P_hy0EIUrO73iXzTjRqEQ_3a8qwRd3x0GHE3cjuiF7SiXyDPEmzSzKVUfVvalE4HDJLpCNKrTRlp8F17.hzIfPEv1tQ87FAUFk5YZt6kbJx1.X3ZNXBSSZPggllp.F.VCrp9FItemJTHE0iqxRJt9fkiJhlGHvMeWdExmV.30F9A46ThtntBj51CgnD3C8CxB277zKFnjYJ8aekcpH9PPMl53kCacernm4ggBg_izbWSdDXNlf7FYir3K9XA2oi49u97eZNZ5IBDCzT9LbbVhONww"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=8e6e79b72f9b6020';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, "\/hc\/en-us?__cf_chl_rt_tk=rCtoHGNUXNjLrg5hhLAt9j8gvCImC4KdU9aPlpi5zdM-1732336766-1.0.1.1-ysRQ3Mbo02ozb3Py3yaeI49wHFQciXUsIobIAagGsrY" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>