Active Diluent-Anion Synergy Strategy Regulating Nonflammable Electrolytes for High-Efficiency Li Metal Batteries

High-energy Li metal batteries (LMBs) consisting of Li metal anodes and high-voltage cathodes are promising candidates of the next generation energy-storage systems owing to their ultrahigh energy density. However, it is still challenging to develop high-voltage nonflammable electrolytes with superior anode and cathode compatibility for LMBs. Here, we propose an active diluent-anion synergy strategy to achieve outstanding compatibility with Li metal anodes and high-voltage cathodes by using 1,2-difluorobenzene (DFB) with high activity for yielding LiF as an active diluent to regulate nonflammable dimethylacetamide (DMAC)-based localized high concentration electrolyte (LHCE-DFB). DFB and bis(fluorosulfonyl)imide (FSI- ) anion cooperate to construct robust LiF-rich solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI), which effectively stabilize DMAC from intrinsic reactions with Li metal anode and enhance the interfacial stability of the Li metal anodes and LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) cathodes. LHCE-DFB enables ultrahigh Coulombic efficiency (98.7 %), dendrite-free, extremely stable and long-term cycling of Li metal anodes in Li || Cu cells and Li || Li cells. The fabricated NCM811 || Li cells with LHCE-DFB display remarkably enhanced long-term cycling stability and excellent rate capability. This work provides a promising active diluent-anion synergy strategy for designing high-voltage electrolytes for high-energy batteries.

Initiator-free in-situ synthesized polymer electrolytes with high ionic conductivity for dendrite-free lithium metal batteries

In-situ preparation of polymer electrolytes (PEs) can enhance electrolyte/electrode interface contact and accommodate the current large-scale production line of lithium-ion batteries (LIBs). However, reactive initiators of in-situ PEs may lead to low capacity, increased impedance and poor cycling performance. Flammable and volatile monomers and plasticizers of in-situ PEs are potential safety risks for the batteries. Herein, we adopt lithium difluoro(oxalate)borate (LiDFOB)-initiated in-situ polymerization of solid-state non-volatile monomer 1,3,5-trioxane (TXE) to fabricate PEs (In-situ PTXE). Fluoroethylene carbonate (FEC) and methyl 2,2,2-trifluoroethyl carbonate (FEMC) with good fire retardance, high flash point, wide electrochemical window and high dielectric constant were introduced as plasticizers to improve ionic conductivity and flame retardant property of In-situ PTXE. Compared with previously reported in-situ PEs, In-situ PTXE exhibits distinct merits, including free of initiators, non-volatile precursors, high ionic conductivity of 3.76 × 10^-3 S cm^-1, high lithium-ion transference number of 0.76, wide electrochemical stability window (ESW) of 6.06 V, excellent electrolyte/electrode interface stability and effectively inhibition of Li dendrite growth on the lithium metal anode. The fabricated LiFePO₄ (LFP)/Li batteries with In-situ PTXE achieve significantly boosted cycle stability (capacity retention rate of 90.4% after 560 cycles) and outstanding rate capability (discharge capacity of 111.7 mAh g^-1 at 3C rate).

Nonflammable Localized High-Concentration Electrolytes with Long-Term Cycling Stability for High-Performance Li Metal Batteries

High-concentration electrolytes (HCEs) can effectively enhance interface stability and cycle performance of Li metal batteries (LMBs). However, HCEs suffer from low ionic conductivity, high viscosity, high cost, and high density. Herein, fluorobenzene (FB) diluted localized high-concentration electrolytes (LHCEs) consisting of lithium bis(fluorosulfonyl)imide (LiFSI)/triethyl phosphate (TEP)/FB are developed. 2.3 M LHCE can reserve concentrated Li⁺-FSI^--TEP solvation structures. Diluent FB possesses low density, low viscosity, low cost, low dielectric constant, low LUMO, and a good fluorine-donating property, which can significantly reduce viscosity, improve ionic conductivity, promote the formation of LiF-rich SEI, and enhance interaction of Li⁺-TEP and Li⁺-FSI^- ion-pairs of the electrolytes. 2.3 M LHCE is a highly safe nonflammable electrolyte. 2.3 M LHCE can effectively inhibit dendrite growth on Li metal anode. 2.3 M LHCE endows LiFePO₄ cells with good rate capability (discharge capacity of 112.7 mAh g^-1 at 5 C rate) and excellent cycling performance (capacity retention of 95.4% after 1000 cycles). 2.3 M LHCE also shows good compatibility with LiNi_0.8Co_0.1Mn_0.1O₂ and exhibits outstanding cycle stability (capacity retention of 86.4% after 500 cycles). Therefore, 2.3 M LHCE is a promising electrolyte for practical applications in LMBs.

POS0701 LONG-TERM EFFICACY OF BARICITINIB IN PATIENTS WITH RHEUMATOID ARTHRITIS WHO HAVE HAD INADEQUATE RESPONSE TO csDMARDs: RESULTS FROM RA-BEYOND UP TO 7 YEARS OF TREATMENT

Background

Baricitinib (BARI), an oral selective Janus kinase 1/2 inhibitor, has demonstrated efficacy in patients (pts) with rheumatoid arthritis (RA) for up to 3 years (yrs) in a long-term extension (LTE) study RA-BEYOND.1

Objectives

Disclose efficacy of BARI in csDMARD-IR pts in the completed LTE study (up to 7 yrs).

Methods

In RA-BUILD, csDMARD-IR pts were randomized 1:1:1 to BARI 4 mg, 2 mg, or placebo (PBO). Completers to week (wk) 24 could enter the LTE and received BARI 4 or 2 mg. In RA-BEAM, MTX-IR pts were randomized 1:1:1 to BARI 4 mg, adalimumab (ADA) 40 mg, or PBO. Completers to wk 52 received BARI 4 mg in the LTE. Pts with no response could be rescued after wk 16 in both studies. Data were analysed by treatment assigned at baseline in originating studies as observed up to time of stepdown (if applicable), study discontinuation or completion, whichever occurred earlier. Efficacy response rates (RR) were assessed as proportions of pts with observed data up to yr 7 (wk 364) for low-disease activity (LDA) (SDAI ≤ 11, DAS28-hsCRP ≤ 3.2, CDAI ≤ 10), remission (REM) (SDAI ≤ 3.3, DAS28-hsCRP < 2.6, CDAI ≤ 2.8, Boolean), and physical function (HAQ-DI ≤ 0.5). No formal statistical comparisons were conducted.

Results

Approximately 56%/25% of pts in BARI 4 mg, 80%/31% in BARI 2 mg, and 60%/25% in PBO from RA-BUILD remained active at yr 3/7; 59%/17% of pts in ADA, 54%/16% in BARI 4 mg, and 67%/14% in PBO from RA-BEAM remained active at year 3/7. SDAI and CDAI had comparable RR for LDA and REM (Table 1). DAS-28CRP LDA RR were similar to SDAI and CDAI, while REM RR were about twice those of SDAI and CDAI (Table 1). HAQ-DI ≤ 0.5 RR was achieved by 25-30% of BARI-treated pts from both trials and maintained to the end of LTE.

Table 1.

Efficacy outcomes in RA-BEYOND

TimeaN/n (%)LDAREMHAQ-DI ≤0.5SDAICDAIDAS-28 CRPSDAICDAIDAS-28 CRPBooleanRA-BEYOND entryBARI 2 mg (BUILD)197/109197/103200/108197/38 (19.3)197/35 (17.8)200/72 (36.0)200/29 (14.5)200/50 (25.0)(55.3)(52.3)(54.0)BARI 4 mg (BUILD)188/113191/116189/112188/33191/35 (18.3)189/75 (39.7)189/26 (13.8)193/44 (22.8)(60.1)(60.7)(59.3)(17.6)BARI 4 mg (BEAM)412/288414/290412/280412/112414/108412/199412/78 (18.9)414/133 (27.3)(69.9)(70.0)(68.0)(27.2)(26.1)(48.3)Yr 3BARI 2 mg (BUILD)156/120158/116156/112156/41 (26.3)158/44 (27.8)156/81 (51.9)156/34 (21.8)159/38 (23.9)(76.9)(73.4)(71.8)BARI 4 mg (BUILD)107/76107/76107/74107/24107/26 (24.3)107/56 (52.3)107/17 (15.9)108/26 (24.1)(71.0)(71.0)(69.2)(22.4)BARI 4 mg (BEAM)222/166224/166222/164222/72224/71 (31.7)222/119222/48224/54 (24.1)(74.8)(74.1)(73.9)(32.4)(53.6)(21.6)Yr 7BARI 2 mg (BUILD)61/5061/4961/5161/17 (27.9)61/18 (29.5)61/40 (65.6)61/12 (19.7)62/16 (25.8)(82.0)(80.3)(83.6)BARI 4 mg (BUILD)45/3748/3745/3445/13 (28.9)48/16 (33.3)45/25 (55.6)45/8 (17.8)48/14 (29.2)(82.2)(77.1)(75.6)BARI 4 mg (BEAM)60/5364/5760/53 (88.3)60/18 (30.0)64/22 (34.4)60/38 (63.3)60/13 (21.7)64/14 (21.9)(88.3)(89.1)

N: Number of pts with observed data; n: Number of pts with response. aTime from randomization in originating studies. Entry to RA-BEYOND=wk 24 and wk 52; Yr 3=wk 156 and wk 160; and Yr 7=wk 360 and wk 364 of RA-BUILD and RA-BEAM, respectively.

Conclusion

In observed data, BARI demonstrated maintained efficacy in treatment and maintenance of physical function of a csDMARDs-IR RA pt population up to 7 yrs.

References

[1]Smolen JS, et al. Rheumatology (Oxford). 2021; 60(5):2256-66.

Disclosure of Interests

Roberto Caporali Speakers bureau: Abbvie, Amgen, BMS, Celltrion, Eli Lilly and Company, Galapagos, Pfizer, Fresenius-Kabi, MSD, UCB, Roche,Janssen, Novartis, Sandoz, Consultant of: Abbvie, Amgen, BMS, Celltrion, Eli Lilly and Company, Galapagos, Pfizer, MSD, UCB, Janssen, Novartis, Sandoz, Daniel Aletaha Speakers bureau: Abbvie, Amgen, Eli Lilly and Company, Janssen, Merck, Novartis, Pfizer, Roche, Sandoz, Grant/research support from: Abbvie, Amgen, Eli Lilly and Company, Novartis, Roche, SoBi, Sanofi, Raimón Sanmartí Speakers bureau: Eli Lilly and Company, Grant/research support from: Eli Lilly and Company, Tsutomu Takeuchi Speakers bureau: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co, Ltd. Daiichi Sankyo Co., Ltd. Eisai Co., Ltd. Eli Lilly Japan K.K.; Gilead Sciences, Inc. Janssen Pharmaceutical K.K.; Mitsubishi-Tanabe Pharma Co.; Novartis Pharma Co.; Pfizer Japan Inc.; Sanofi K.K.; UCB Japan Co., Ltd., Consultant of: AbbVie Japan GK, Astellas Pharma, Inc.; Chugai Pharmaceutical Co, Ltd.; Eli Lilly Japan K.K.; Eisai Co., Ltd.; Gilead Sciences, Inc.; Janssen Pharmaceutical K.K.; Mitsubishi-Tanabe Pharma Corp., Pfizer Japan Inc., Grant/research support from: AbbVie Japan GK, Asahikasei Pharma Corp., Chugai Pharmaceutical Co, Ltd., DNA Chip Research Inc.; Eisai Co., Ltd., Eli Lilly Japan K.K.; Mitsubishi-Tanabe Pharma Corp., UCB Japan Co., Ltd., Daojun Mo Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Ewa Haladyj Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Liliana Zaremba-Pechmann: None declared, Peter C. Taylor Consultant of: AbbVie, Biogen, Eli Lilly and Company, Fresenius, Galapagos, Gilead Sciences, GlaxoSmithKline, Janssen, Nordic Pharma, Pfizer Inc, Roche, and Sanofi, Grant/research support from: Celgene, and Galapagos

POS0682 LONG-TERM EFFICACY OF BARICITINIB IN PATIENTS WITH RHEUMATOID ARTHRITIS WITH INADEQUATE RESPONSE TO bDMARDs: RESULTS FROM RA-BEYOND FOLLOWING 6.9 YEARS OF TREATMENT

Background

Baricitinib (BARI), an oral selective Janus kinase 1/2 inhibitor, is approved for treatment of adults with moderately-to-severely active rheumatoid arthritis (RA). BARI demonstrated efficacy in patients (pts) with RA who have inadequate response to biologic disease-modifying antirheumatic drugs (bDMARD-IR) in a 24-week (wk) phase 3 study, RA-BEACON.1 BARI efficacy was evaluated up to 3 years (yrs) of treatment in a long-term extension (LTE) study, RA-BEYOND.2

Objectives

Disclose long-term efficacy of BARI 4 mg and 2 mg in bDMARD-IR pts in the completed study RA-BEYOND.

Methods

In RA-BEACON, pts were randomized 1:1:1 to BARI 4 mg, 2 mg, or PBO; pts with no response could be rescued after wk 16. Completers to wk 24 could enter with BARI 4 or 2mg RA-BEYOND for up to 360 wks (6.9 yrs). LTE data were analysed by treatment assigned at baseline in RA-BEACON as observed up to time of stepdown (if applicable), study discontinuation, or study completion, whichever occurred earlier. Efficacy response rates (RR) were assessed as proportions of pts with observed data up to wk 360 for low-disease activity (LDA) (SDAI ≤ 11, DAS28-hsCRP ≤ 3.2, CDAI ≤ 10), remission (REM) (SDAI ≤ 3.3, DAS28-hsCRP < 2.6, CDAI ≤ 2.8, Boolean), and physical functioning (HAQ-DI ≤ 0.5). No formal statistical comparisons were conducted.

Results

156, 152, and 140 pts entered the LTE (4 mg, 2 mg, and PBO, respectively). Pts in BARI 4 and 2 mg arms had higher LDA and REM RR vs PBO at LTE entry (wk 24) (Table 1). PBO-treated pts achieved comparable RR to pts in the BARI 4 mg arm by wk 48 (24 wks after switch to BARI 4 mg) and up to wk 360. Of pts enrolled to RA-BEYOND, approx. 50% in BARI 4 mg, 65% in 2 mg and 61% in PBO remained active at wk 156; 17%, 26% and 26% at wk 360, respectively. SDAI LDA RR were 47%/70% and 61%/74% for pts treated with BARI 4 mg and 2 mg, at wk 156 (yr 3)/ 360 (yr 6.9), respectively; SDAI REM RR were 15%/26% and 26%/26% for BARI 4 mg and 2 mg, at wk 156/360, respectively (Table 1). SDAI and CDAI had comparable RR. DAS-28CRP LDA RR were similar to SDAI and CDAI, while REM RR were about twice those of SDAI and CDAI. HAQ-DI ≤ 0.5 RR was 15%/26% (BARI 4 mg), 21%/15% (BARI 2mg), and 9%/3% (PBO) at 3/6.9 yrs.

Table 1.

Efficacy outcomes in RA-BEYOND

TimeaN/n (%)LDAREMSDAICDAIDAS-28 CRPSDAICDAIDAS-28 CRPBooleanHAQ-DI ≤0.5Wk 24PBOb135/31 (23.0)138/32 (23.2)135/31 (23.0)135/6 (4.4)138/8 (5.8)135/14 (10.4)135/3139/6 (4.3)(2.2)BARI 2 mg148/42 (28.4)152/43 (28.3)148/38 (25.7)148/10 (6.8)152/10 (6.6)148/22 (14.9)148/9152/17 (11.2)(6.1)BARI 4 mg150/57 (38.0)156/60 (38.5)150/60 (40.0)150/14 (9.3)156/17 (10.9)150/37 (24.7)150/11 (7.3)156/17 (10.9)Wk 48PBO128/59 (46.1)129/58 (45.0)128/58 (45.3)128/14 (10.9)129/15 (11.6)128/31 (24.2)128/5130/6 (4.6)(3.9)BARI 2 mg139/54 (38.8)140/56 (40.0)139/53 (38.1)139/13 (9.4)140/14 (10.0)139/30 (21.6)139/11 (7.9)140/16 (11.4)BARI 4 mg147/70 (47.6)149/71 (47.7)147/68 (46.3)147/22 (15.0)149/19 (12.8)147/49 (33.3)147/14 (9.5)149/19 (12.8)Wk 156PBO84/47 (56.0)85/47 (55.3)84/45 (53.6)84/15 (17.9)85/14 (16.5)84/33 (39.3)84/985/8 (9.4)(10.7)BARI 2 mg98/60 (61.2)99/60 (60.6)98/58 (59.2)98/25 (25.5)99/27 (27.3)98/43 (43.9)98/13 (13.3)99/21 (21.2)BARI 4 mg76/36 (47.4)78/35 (44.9)76/37 (48.7)76/11 (14.5)78/13 (16.7)76/25 (32.9)76/978/12 (15.4)(11.8)Wk 360PBO33/26 (78.8)35/25 (71.4)34/27 (79.4)33/8 (24.2)35/9 (25.7)34/17 (50.0)34/636/1 (2.8)(17.6)BARI 2 mg38/28 (73.7)38/28 (73.7)38/27 (71.1)38/10 (26.3)38/8 (21.1)38/20 (52.6)38/539/6 (15.4)(13.2)BARI 4 mg27/19 (70.4)27/20 (74.1)27/20 (74.1)27/7 (25.9)27/7 (25.9)27/15 (55.6)27/427/7 (25.9)(14.8)

N: Number of pts with observed data; n: Number of pts with response. aNumber of wks from randomisation. bTreatment groups as assigned at randomisation.

Conclusion

In observed data, BARI maintained efficacy and normative physical function bDMARD-IR population up to 6.9 yrs (360 wks).

References

[1]Genovese MC et al. N Engl J Med. 2016; 374:1243-52

[2]Wells AF et al. Rheumatol Ther. 2021; 8:987–1001

Disclosure of Interests

Roberto Caporali Speakers bureau: Abbvie, Amgen, BMS, Celltrion, Eli Lilly and Company, Galapagos, Pfizer, Fresenius-Kabi, MSD, UCB, Roche,Janssen, Novartis, Sandoz, Consultant of: Abbvie, Amgen, BMS, Celltrion, Eli Lilly and Company, Galapagos, Pfizer, MSD, UCB, Janssen, Novartis, Sandoz, Daniel Aletaha Speakers bureau: Abbvie, Amgen, Eli Lilly and Company, Janssen, Merck, Novartis, Pfizer, Roche, Sandoz, Grant/research support from: Abbvie, Amgen, Eli Lilly and Company, Novartis, Roche, SoBi, Sanofi, Raimón Sanmartí Speakers bureau: Eli Lilly and Company, Grant/research support from: Eli Lilly and Company, Tsutomu Takeuchi Speakers bureau: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co, Ltd. Daiichi Sankyo Co., Ltd. Eisai Co., Ltd. Eli Lilly Japan K.K.; Gilead Sciences, Inc. Janssen Pharmaceutical K.K.; Mitsubishi-Tanabe Pharma Co.; Novartis Pharma Co.; Pfizer Japan Inc.; Sanofi K.K.; UCB Japan Co., Ltd., Consultant of: AbbVie Japan GK, Astellas Pharma, Inc.; Chugai Pharmaceutical Co, Ltd.; Eli Lilly Japan K.K.; Eisai Co., Ltd.; Gilead Sciences, Inc.; Janssen Pharmaceutical K.K.; Mitsubishi-Tanabe Pharma Corp., Pfizer Japan Inc., Grant/research support from: AbbVie Japan GK, Asahikasei Pharma Corp., Chugai Pharmaceutical Co, Ltd., DNA Chip Research Inc.; Eisai Co., Ltd., Eli Lilly Japan K.K.; Mitsubishi-Tanabe Pharma Corp., UCB Japan Co., Ltd., Daojun Mo Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Ewa Haladyj Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Liliana Zaremba-Pechmann: None declared, Peter C. Taylor Consultant of: AbbVie, Biogen, Eli Lilly and Company, Fresenius, Galapagos, Gilead Sciences, GlaxoSmithKline, Janssen, Nordic Pharma, Pfizer Inc, Roche, and Sanofi, Grant/research support from: Celgene and Galapagos

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Effects of Halogenated End Groups on the Performance of Nonfullerene Acceptors

The end groups' halogenations among the nonfullerene acceptors (NFAs) were a very useful method to fabricate high-performance NFAs-based organic solar cells (OSCs). We report three high-performance NFAs, BTIC-4EO-4F, BTIC-4EO-4Cl, and BTIC-4EO-4Br. They all have a fused benzothiadiazole as the core unit and different dihalogenated end groups (IC-2F, IC-2Cl, and IC-2Br) as the terminal unit. Thanks to the improved intramolecular charge-transfer ability of the brominated NFAs, bromination is more effective than fluorination and chlorination in lowering the energy levels and red-shifting the absorption spectra of the resulting NFAs. When compared with the chlorinated and fluorinated counterparts, the BTIC-4EO-4Br blend films exhibit lower roughness, better phase separation size, and stronger face-on stacking. When blended with poly{[4,8-bis[5-(2-ethylhexyl)-4-fluoro-2-thienyl]benzo[1,2-b:4,5-b']-dithiophene-2,6-diyl]-alt-[2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]]} (PBDB-TF) as the polymer donor material, the BTIC-4EO-4Br-based OSCs exhibit the highest power conversion efficiency (12.41%), with a higher current density and a higher open-circuit voltage than the BTIC-4EO-4Cl-based OSCs (11.29%) and BTIC-4EO-4F-based OSCs (10.64%). These results show that the bromination of the NFAs' electron-withdrawing end groups can also be very effective in constructing high-performance photovoltaic materials.

Chlorinated Benzo[1,2-b:4,5-c']dithiophene-4,8-dione Polymer Donor: A Small Atom Makes a Big Difference

The position of a chlorine atom in a charge carrier of polymer solar cells (PSCs) is important to boost their photovoltaic performance. Herein, two chlorinated D-A conjugated polymers PBBD-Cl-α and PBBD-Cl-β are synthesized based on two new building blocks (TTO-Cl-α and TTO-Cl-β) respectively by introducing the chlorine atom into α or β position of the upper thiophene of the highly electron-deficient benzo[1,2-b:4,5-c']dithiophene-4,8-dione moiety. Single-crystal analysis demonstrates that the chlorine-free TTO shows a π-π stacking distance (d π-π) of 3.55 Å. When H atom at the α position of thiophene of TTO is replaced by Cl, both π-π stacking distance (d π-π = 3.48 Å) and Cl···S distance (d Cl-S = 4.4 Å) are simultaneously reduced for TTO-Cl-α compared with TTO. TTO-Cl-β then showed the Cl···S non-covalent interaction can further shorten the intermolecular π-π stacking separation to 3.23 Å, much smaller than that of TTO-Cl-α and TTO. After blending with BTP-eC9, PBBD-Cl-β:BTP-eC9-based PSCs achieved an outstanding power conversion efficiency (PCE) of 16.20%, much higher than PBBD:BTP-eC9 (10.06%) and PBBD-Cl-α:BTP-eC9 (13.35%) based devices. These results provide an effective strategy for design and synthesis of highly efficient donor polymers by precise positioning of the chlorine substitution.

Synergistic Effect of Alkyl Chain and Chlorination Engineering on High-Performance Nonfullerene Acceptors

In this work, three new nonfullerene acceptors (BT₆IC-BO-4Cl, BT₆IC-HD-4Cl, and BT₆IC-OD-4Cl), which comprise a central fused benzothiadiazole core and two dichlorinated end groups and substituted with different branched alkyl chains [2-butyloctyl (BO), longer 2-hexyldecyl (HD), and 2-octyldodecyl (OD)], are successfully designed and prepared. The influences of the branched alkyl chain with different lengths on the electronic/optoelectronic property, electrochemistry, and photovoltaic performance are systematically investigated. It has been revealed that BT₆IC-HD-4Cl, which had the medium alkyl chain (2-hexyldecyl) length, has the best photovoltaic performance when using PDBT-TF as the electron donor. The BT₆IC-HD-4Cl-based device shows an impressive power conversion efficiency of 14.90%, much higher than BT₆IC-BO-4Cl (14.45%)- and BT₆IC-OD-4Cl (9.60%)-based devices. All these evidence shows that the subtle changes in the alkyl substituent of these high-performance chlorinated acceptors can have a big impact on the structural order and molecular packing of the resultant nonfullerene acceptors and ultimately on the photovoltaic performance of the final solar devices.

FRI0123 SAFETY PROFILE OF BARICITINIB FOR THE TREATMENT OF RHEUMATOID ARTHRITIS UP TO 8.4 YEARS: AN UPDATED INTEGRATED SAFETY ANALYSIS

Background:

Baricitinib (bari) is an oral selective inhibitor of Janus kinase (JAK) 1 and 2, approved for the treatment of moderately to severely active rheumatoid arthritis (RA) in adults.

Objectives:

Here we update the drug’s safety profile with data up to 8.4 years of treatment.

Methods:

Long-term safety of bari was assessed from 9 completed randomized trials (5 Ph3, 3 Ph2, 1 Ph 1b) and 1 ongoing long-term extension (LTE) study. Incidence rates (IR) per 100 patient-years (PY) were calculated for all patients with RA treated with ≥1 dose of bari through 1-Sep-2019 (All-Bari-RA analysis set). IRs for deep vein thrombosis (DVT), pulmonary embolism (PE), and DVT and/or PE (DVT/PE) were also calculated for groups of patients while receiving bari 2mg or bari 4mg within All-Bari-RA. Major adverse cardiovascular events (MACE) were adjudicated in 5 phase 3 studies and the LTE.

Results:

3770 pts received bari for 13,148 PY, with a median and maximum exposure of 4.2 and 8.4 years, respectively. Overall IRs per 100 PY were: for any treatment-emergent adverse event (AE)(25.8); serious AE (including death)(7.2); temporary interruption due to AE (9.5); permanent discontinuation due to AE (4.8); death (0.52); serious infection (2.7); opportunistic infection (0.44) (excluding tuberculosis [TB], including multidermatomal herpes zoster [HZ]); TB (0.15); HZ (3.0); MACE (0.50); DVT (0.31); PE (0.24); DVT/PE (0.45); malignancies excluding non-melanoma skin cancer (NMSC) (0.90); NMSC (0.33); lymphoma (0.06); and gastrointestinal perforation (0.04). Incidence rates (IR)[95% confidence intervals] for patients while receiving bari 2mg (N=1077) and bari 4mg (N=3400) were DVT 2mg (0.38) [0.18, 0.73] and 4mg (0.30) [0.21, 0.43]; PE 2mg (0.26) [0.09, 0.56] and 4mg (0.25) [0.16, 0.36]; and DVT/PE 2mg (0.47) [0.23, 0.84] and 4mg (0.46) [0.34, 0.61]. IRs for death tended to increase in later time intervals (beyond 192 weeks). No particular cause of death contributed to this increase. For all other safety topics of interest, across 48-week treatment intervals, IRs remained stable over time. Across safety topics, IRs were consistent with previous analyses1,2.

Conclusion:

In this update with 3,021 additional PY of exposure, bari maintained a safety profile similar to that previously reported,1,2with no increase of IRs across safety topics through exposures up to 8.4 years.

References:

[1]Smolen JS et al. J Rheumatol. 2019 Jan;46(1):7-18

[2]Genovese MC et al. Ann Rheum Dis. 2019 78(supp. 2):A308

Table.n/NARIRTreatment emergent AE3391/377025.8Serious AE (including death)940/37707.2Temporary d/c due to AE1241/36479.5Permanent d/c due to AE644/37704.8Death69/37700.52Serious infection344/37702.7Opportunistic infection (excluding tuberculosis, including multidermatomal herpes zoster)59/37700.44Herpes zoster384/37703.0Tuberculosis20/37700.15Major adverse cardiovascular events*63/32510.50DVT41/37700.31PE32/37700.24DVT and/or PE60/37700.45Malignancies excluding NMSC120/37700.90NMSC44/37700.33Lymphoma8/37700.06Gastrointestinal perforation6/37700.04

*studies with positive adjudication. AE=adverse event; D/C= discontinuation; DVT=deep vein thrombosis; IR=incidence rate; NAR=number of patients at risk; NMSC=non-melanoma skin cancer; PE=pulmonary embolism

Disclosure of Interests:

Mark C. Genovese Grant/research support from: Abbvie, Eli Lilly and Company, EMD Merck Serono, Galapagos, Genentech/Roche, Gilead Sciences, Inc., GSK, Novartis, Pfizer Inc., RPharm, Sanofi Genzyme, Consultant of: Abbvie, Eli Lilly and Company, EMD Merck Serono, Genentech/Roche, Gilead Sciences, Inc., GSK, Novartis, RPharm, Sanofi Genzyme, Josef S. Smolen Grant/research support from: AbbVie, AstraZeneca, Celgene, Celltrion, Chugai, Eli Lilly, Gilead, ILTOO, Janssen, Novartis-Sandoz, Pfizer Inc, Samsung, Sanofi, Consultant of: AbbVie, AstraZeneca, Celgene, Celltrion, Chugai, Eli Lilly, Gilead, ILTOO, Janssen, Novartis-Sandoz, Pfizer Inc, Samsung, Sanofi, Tsutomu Takeuchi Grant/research support from: Eisai Co., Ltd, Astellas Pharma Inc., AbbVie GK, Asahi Kasei Pharma Corporation, Nippon Kayaku Co., Ltd, Takeda Pharmaceutical Company Ltd, UCB Pharma, Shionogi & Co., Ltd., Mitsubishi-Tanabe Pharma Corp., Daiichi Sankyo Co., Ltd., Chugai Pharmaceutical Co. Ltd., Consultant of: Chugai Pharmaceutical Co Ltd, Astellas Pharma Inc., Eli Lilly Japan KK, Speakers bureau: AbbVie GK, Eisai Co., Ltd, Mitsubishi-Tanabe Pharma Corporation, Chugai Pharmaceutical Co Ltd, Bristol-Myers Squibb Company, AYUMI Pharmaceutical Corp., Eisai Co., Ltd, Daiichi Sankyo Co., Ltd., Gilead Sciences, Inc., Novartis Pharma K.K., Pfizer Japan Inc., Sanofi K.K., Dainippon Sumitomo Co., Ltd., Gerd Rüdiger Burmester Consultant of: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Speakers bureau: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Walter Deberdt Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Douglas Schlichting Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Hongsuk Song Employee of: Syneos Health under contract to Eli Lilly and Company, Daojun Mo Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Chad Walls Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Kevin Winthrop Grant/research support from: Bristol-Myers Squibb, Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Galapagos, Gilead, GSK, Pfizer Inc, Roche, UCB

Bromination: An Alternative Strategy for Non-Fullerene Small Molecule Acceptors

The concept of bromination for organic solar cells has received little attention. However, the electron withdrawing ability and noncovalent interactions of bromine are similar to those of fluorine and chlorine atoms. A tetra-brominated non-fullerene acceptor, designated as BTIC-4Br, has been recently developed by introducing bromine atoms onto the end-capping group of 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile and displayed a high power conversion efficiency (PCE) of 12%. To further improve its photovoltaic performance, the acceptor is optimized either by introducing a longer alkyl chain to the core or by modulating the numbers of bromine substituents. After changing each end-group to a single bromine, the BTIC-2Br-m-based devices exhibit an outstanding PCE of 16.11% with an elevated open-circuit voltage of V oc = 0.88 V, one of the highest PCEs reported among brominated non-fullerene acceptors. This significant improvement can be attributed to the higher light harvesting efficiency, optimized morphology, and higher exciton quenching efficiencies of the di-brominated acceptor. These results demonstrate that the substitution of bromine onto the terminal group of non-fullerene acceptors results in high-efficiency organic semiconductors, and promotes the use of the halogen-substituted strategy for polymer solar cell applications.

A Benzo[1,2-b:4,5-c']Dithiophene-4,8-Dione-Based Polymer Donor Achieving an Efficiency Over 16

It is of great significance to develop efficient donor polymers during the rapid development of acceptor materials for nonfullerene bulk-heterojunction (BHJ) polymer solar cells. Herein, a new donor polymer, named PBTT-F, based on a strongly electron-deficient core (5,7-dibromo-2,3-bis(2-ethylhexyl)benzo[1,2-b:4,5-c']dithiophene-4,8-dione, TTDO), is developed through the design of cyclohexane-1,4-dione embedded into a thieno[3,4-b]thiophene (TT) unit. When blended with the acceptor Y6, the PBTT-F-based photovoltaic device exhibits an outstanding power conversion efficiency (PCE) of 16.1% with a very high fill factor (FF) of 77.1%. This polymer also shows high efficiency for a thick-film device, with a PCE of ≈14.2% being realized for an active layer thickness of 190 nm. In addition, the PBTT-F-based polymer solar cells also show good stability after storage for ≈700 h in a glove box, with a high PCE of ≈14.8%, which obviously shows that this kind of polymer is very promising for future commercial applications. This work provides a unique strategy for the molecular synthesis of donor polymers, and these results demonstrate that PBTT-F is a very promising donor polymer for use in polymer solar cells, providing an alternative choice for a variety of fullerene-free acceptor materials for the research community.

Chlorination vs. fluorination: a study of halogenated benzo[c][1,2,5]thiadiazole-based organic semiconducting dots for near-infrared cellular imaging

The chlorinated dots based on chlorinated benzo[c][1,2,5]thiadiazole unit possess higher fluorescence quantum yields, larger Stokes shifts, and better photostability than the fluorinated dots.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

First principle study on the predicted phase transition of MN (M = Zr, La and Th)

First principle (FP) calculations were performed to systematically study the structural properties of ZrN, LaN and ThN with GGA correction. The ground state properties, wave velocities and Debye temperature of B1, P6₃/mmc, Pnma and B2 phase in ZrN, LaN and ThN were investigated and agree well with other theoretical and experimental results. More importantly, some novel phases are predicted in these materials, i.e. with the increasing pressure the phase transition sequence in ZrN and ThN is found to be B1  →  P6₃/mmc  →  B2 phase, while in LaN, the sequence of B1  →  Pnma  →  B2 is observed. Furthermore, our calculated elastic properties also confirm the prediction of phase transition under high pressure. These phase transitions arise from the optical phonon softening of B1 at around X, M and G points of Brillouin zone and P6₃/mmc (or Pnma) structure at around G, and H-K points.

Highly stable and bright fluorescent chlorinated polymer dots for cellular imaging

Chlorinated semiconducting polymer dots (Pdots) are reported. The Pdots showed a quantum yield of 20.3%, which is about two times higher than that of non-chlorinated Pdots (8.5%).

The integrated adjustment of chlorine substitution and two-dimensional side chain of low band gap polymers in organic solar cells

The chlorination and side-chain extension of benzothiadiazole derivatives can finely manipulate the open-circuit voltage in their solar cells.

Obesity and glycemic control in patients with diabetes mellitus: Analysis of physician electronic health records in the US from 2009-2011

AIMS

Examine the association between obesity and glycemic control among patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM).

METHODS

Data from US physician electronic health records (Humedica®) from 2009-2011 were utilized. Patients were defined as having above-target glycemic control if they had an HbA1c ≥7% at any time during the study period. Multinomial logistic regressions were conducted separately for T1DM and T2DM patients, and examined associations between BMI categories and probability of having above-target glycemic control (≥7% and <8%, ≥8% and <9%, or ≥9%) while controlling for patient demographics, general health, comorbid conditions, and antihyperglycemic medication use.

RESULTS

There were 14,028 T1DM and 248,567 T2DM patients; 47.8% of T1DM and 63.4% of T2DM were obese (BMI ≥30kg/m(2)). For T1DM, being overweight (BMI 25-<30), obese class I (30-<35), II (35-<40), or III (≥40) was associated with a significantly higher probability of having HbA1c≥8% and <9% or ≥9%, while being overweight was associated with a significantly higher probability of having HbA1c ≥7% and <8% compared to normal BMI (BMI≥18.5 and<25). For T2DM patients, being overweight, obese class I, II, or III was associated with a significantly higher probability of having HbA1c ≥7% and <8%, ≥8% and <9%, or ≥9%.

CONCLUSIONS

For both T1DM and T2DM patients, there were positive and statistically significant associations between being overweight or obese and having suboptimal glycemic control. These findings quantify the associations between obesity and glycemic control, and highlight the potential importance of individual characteristics on glycemic control.

Electrosynthesis and electrochemical capacitive behavior of a new nitrogen PEDOT analogue-based polymer electrode

As a supercapacitor electrode, a new nitrogen PEDOT analogue (PMDTO) exhibited some outstanding electrochemical performances but still suffered some drawbacks.

Synthesis and characterization of chiral PEDOT enantiomers bearing chiral moieties in side chains: chiral recognition and its mechanism using electrochemical sensing technology

This manuscript reports a couple of novel polymers of side-chain functionalized PEDOT. The new polymers can be employed to successfully recognize 3,4-dihydroxyphenylalanine enantiomers and we also discuss the mechanism of chiral recognition.

Solvent effects on electrosynthesis, morphological and electrochromic properties of a nitrogen analog of PEDOT

A new nitrogen analog of 3,4-ethylenedioxythiophene (EDOT), N-methyl-3,4-dihydrothieno[3,4-b][1,4]oxazine (MDTO), was electropolymerized in different solvents (deionized water, acetonitrile, and propylene carbonate) using LiClO4 as the electrolyte. The structure and performance of as-prepared PMDTO polymers were systematically studied by cyclic voltammetry, UV-vis spectroscopy, FT-IR, SEM, thermogravimetry, spectroelectrochemistry and electrochromic techniques. To our surprise, solvents had a major influence on the electropolymerization of MDTO and properties of the resultant polymers, including morphology, electrochemistry, electronic and optical properties, and electrochromics, etc. In aqueous solution, MDTO revealed the lowest onset oxidation potential (0.19 V) than in acetonitrile (0.48 V) and propylene carbonate (0.49 V). However, PMDTO films showed rather poor cycling stability in water, while outstanding stability in acetonitrile and propylene carbonate. Films prepared in propylene carbonate displayed a rather smooth morphology, lower band gap (1.65 eV), higher transparency (97.3%) and a contrast ratio (44.6%) at λ = 466 nm. PMDTO films obtained in acetonitrile showed significantly higher coloration efficiency (169.5 cm(2) C(-1)) than in other two solvents (∼ 97.6 cm(2) C(-1)) with a moderate contrast ratio (24.5%).

One-step template-free electrodeposition of novel poly(indole-7-carboxylic acid) nanowires and their high capacitance properties

Novel poly(indole-7-carboxylic acid) nanowires shows remarkable specific capacitance (373.2 F g⁻¹) and excellent cycle life (91% retention after 1000 cycles).

Poly(thieno[3,4-b]-1,4-oxathiane): medium effect on electropolymerization and electrochromic performance

The asymmetrical sulfur analog of 3,4-ethylenedioxythiophene (EDOT), thieno[3,4-b]-1,4-oxathiane (EOTT), was synthesized, and its electropolymerization was comparatively investigated by employing different solvent-electrolyte systems (room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6), CH2Cl2-Bu4NPF6, and CH2Cl2-BmimPF6). Further, the effect of solvents and supporting electrolytes on the structure, morphology, electrochemical, electronic, and optical properties and electrochromic performance of the obtained poly(thieno[3,4-b]-1,4-oxathiane) (PEOTT) films were minutely studied. PEOTT film with a band gap (Eg) of about 1.6 eV could be facilely electrodeposited in all the solvent-electrolytes and displayed excellent electroactivity, outstanding redox stability in a wide potential window, and improved thermal stability. Cyclic voltammetry showed that EOTT could be electropolymerized at a lower oxidation potential in BmimPF6 (∼1.0 V vs Ag/AgCl) due to several advantanges of RTIL BmimPF6 itself, such as high intrinsic conductivity and mild chemical conditions, etc., and the resulting PEOTT film exhibited compact morphology with better electroactivity and stability and higher electrical conductivity. On the other hand, PEOTT films from all the sovent-electrolytes also showed the electrochromic nature by color changing from gray blue to green, and further kinetic studies revealed that PEOTT had decent contrast ratios (36%), higher coloration efficiencies (212 cm(2)/C in BmimPF6), low switching voltages, moderate response time (1.2 s), excellent stability, and color persistence. From these results, PEOTT provides more plentiful electrochromic colors and holds promise for display applications.

Quantitative assessment of external carotid artery territory supply with modified vessel-encoded arterial spin-labeling

BACKGROUND AND PURPOSE

In patients with carotid stenosis or occlusion, cerebral blood could be supplied through collateral pathways to improve regional blood flow and protect against ischemic events. The contribution of collaterals from the ICA can be assessed by depiction of vascular perfusion territories with ASL. However, so far there is no method available to evaluate the collateral perfusion territory from the ECA in MR imaging. In this study, we present a new labeling scheme based on VE-ASL to quantitatively assess the perfusion territory of the ECA.

MATERIALS AND METHODS

A new labeling approach with a Hadamard encoding scheme was developed to label major arteries, especially the ECA. Twelve healthy subjects with normal cerebrovascular anatomy were examined to demonstrate their perfusion territories. Eight patients with carotid artery stenosis or occlusion were assessed before and after surgery to show changes of their collateral blood supply.

RESULTS

The proposed method enables assessment of the perfusion territories of the ECA. Good agreement was found between the vascular territories and normal cerebrovascular anatomy in healthy subjects. For the patients with carotid stenosis or occlusion, our noninvasive results provided information on collateral flow comparable with that from DSA. Their collateral flows from the ECA, moreover, could be quantitatively estimated pre- and postoperatively.

CONCLUSIONS

The modified approach has been validated by the consistency of collateral perfusion territories with cerebrovascular anatomy, and quantitative assessment of collaterals proved useful for assisting in evaluating therapeutic interventions.

Preferencia de Tadalafilo vs Sildenafilo en pacientes españoles con disfunción eréctil: resultados procedentes de un estudio multicéntrico internacional

OBJECTIVE

To compare patient preference for sildenafil citrate (sildenafil) vs. tadalafil and for their respective dosing instructions in a cohort of Spanish patients with erectile dysfunction (ED).

MATERIAL AND METHODS

Sixty four Spanish patients from a multicenter, two period, cross-over, double-blind study (265 patients enrolled in total) were randomized to receive on-demand sildenafil 50 mg or tadalafil 20 mg for 12 weeks and afterwards were crossed over to the alternate regimen for another 12 weeks to assess drug preference in an extension period of the study. Similarly, to evaluate preference for their respective dosing instructions, 30 patients were randomized to one of the 2 arms treated with tadalafil: one with sildenafil (S) dosing instructions and the other with tadalafil (T) dosing instructions.

RESULTS

Seventy percent of 56 patients completing the study chose to receive tadalafil treatment versus sildenafil treatment (30%) in the extension period (p<0.01). Correspondingly, 73% of 13 evaluating each drug dosing instructions preferred T dosing instructions (p>0.05). Preference did not vary with age, concomitant diseases and previous use of sildenafil.

CONCLUSIONS

In this study, 7 out of 10 patients preferred tadalafil and its dosing instructions to sildenafil, for the treatment of their ED.

Efficacy of tadalafil in the treatment of erectile dysfunction in hypertensive men on concomitant thiazide diuretic therapy

Many men with erectile dysfunction (ED) have hypertension as a comorbid condition. Recent guidelines recommend thiazide diuretics as first-line therapy for hypertension. We analyzed data from 14 randomized, double-blind, placebo-controlled trials (N=2501) to evaluate the efficacy of tadalafil 20 mg for the treatment of ED in men on thiazides. Of the 2501 patients, 163 were on concomitant thiazides (116 tadalafil/47 placebo) and 159 (98%) were reported to have hypertension. The primary efficacy measures were mean change from baseline in the international index of erectile function (IIEF) erectile function (EF) domain and the proportion of 'yes' responses to sexual encounter profile (SEP) Questions 2 and 3. The tadalafil group showed a significantly (P<0.001) greater mean baseline to endpoint improvement on all efficacy outcome measures compared to placebo-treated patients regardless of concomitant thiazide use. More importantly, the responses to tadalafil were similar regardless of concomitant thiazide use. Additionally, responses to tadalafil were comparable between thiazide and nonthiazide users regardless of baseline ED severity (P>0.05).

Injury mortality risk assessment and targeting the subpopulations for prevention in the Northwest Territories, Canada

BACKGROUND AND OBJECTIVE

Prevention of injury mortality is a top priority for public health in the Northwest Territories, Canada. However, the frequency of injury mortality may not be evenly distributed in subgroups. Assessment of population relative risk of injury mortality can assist in better targeting of prevention programs.

METHODS

A population-based case-control study consisting of 197 cases was used to quantify the relative risks of injury mortality for variables age, sex, ethnicity, geographic location and remoteness.

RESULTS

A multivariate logistic model showed that the odds ratios were 2.90 (95% CI 2.09-4.03) for males, 3.39 (95% CI 2.55-4.52) for age group 15-64 years, 11.50 (95% CI 6.47-20.42) for age group over 64 years, 1.51 (95% CI 1.13-2.02) for people in remote communities, and 2.04 (95% CI 1.50-2.79) for people above 66 degrees latitude. Aboriginal people of Dene and Inuit presented increased risks in the stratified analysis by community remoteness and latitude.

CONCLUSIONS

Males, over age 14, living in remote communities, living in the far north, and being aboriginal were at higher risk of injury mortality. Based on the relative risks of injury mortality and the population size in each subpopulation, injury prevention investments should be extended to remote communities.

[Study on the elements in cosmetics by microwave digestion-iCP-AES I. The determination of Pb, As, Cr, Cd, Sr, Bi and Se in solid state cosmetics]

A safe and effective method for the microwave digestion of solid state cosmetic samples is described. The overall digestion conditions, including pressure, power, acids and time of digestion were evaluated by analysing Pb, As, Cr, Cd, Sr, Bi and Se of routine samples with ICP-AES. This method was applied to the determination of certified materials with good agreement.

Recombinant influenza A virus vaccines for the pathogenic human A/Hong Kong/97 (H5N1) viruses

Recombinant reassortment technology was used to prepare H5N1 influenza vaccine strains containing a modified hemagglutinin (HA) gene and neuraminidase gene from the A/Hong Kong/156/97 and A/Hong Kong/483/97 isolates and the internal genes from the attenuated cold-adapted A/Ann Arbor/6/60 influenza virus strain. The HA cleavage site (HA1/HA2) of each H5N1 isolate was modified to resemble that of "low-pathogenic" avian strains. Five of 6 basic amino acids at the cleavage site were deleted, and a threonine was added upstream of the remaining arginine. The H5 HA cleavage site modification resulted in the expected trypsin-dependent phenotype without altering the antigenic character of the H5 HA molecule. The temperature-sensitive and cold-adapted phenotype of the attenuated parent virus was maintained in the recombinant strains, and they grew to 108.5-9.4 EID50/mL in eggs. Both H5N1 vaccine virus strains were safe and immunogenic in ferrets and protected chickens against wild-type H5N1 virus challenge.