Background Blood donations must be tested for evidence of syphilis, a transfusion‐transmitted infection. Screening blood for syphilis‐related antibodies greatly reduced the risk of transfusion‐transmitted syphilis (TTS). It is commonly believed that Treponema pallidum (Tp), the bacterium causing syphilis, does not survive in blood during cold storage—suggested as one reason why no cases of TTS have been recognized in the United States for many years. Some have suggested that routine syphilis screening of blood donations is no longer needed. To address the effect of storage, we investigated the survival of Tp experimentally spiked into blood and platelets stored under conventional conditions. Study design and methods We spiked fresh human blood products with high concentrations of Tp and inoculated samples at intervals into rabbits, a sensitive assay detecting infectious Tp. We tested whole blood (WB) stored refrigerated (1–6°C) for 9 days and platelets stored at room temperature for 7 days or refrigerated for 14 days. We assayed sera of the rabbits collected at intervals for seroconversion using two different tests and assessed orchitis. Rabbits were considered infected if one or both serological test results became positive. Results Viable Tp survived 7 days in WB and 6 days in platelets stored at both ambient and cold temperatures. Discussion Tp at concentrations much higher than those possibly present in an infected blood unit survived in cold blood products longer than previously reported and, thus, storage conditions cannot be relied upon to eliminate T. pallidum from blood or platelets. TTS remains a topic of concern for public health.

In this research work, a theoretical analysis of the photovoltaic properties of nonfullerene organic solar cells is performed. Four molecules have been designed by incorporating different donor units around the central cyanobenzene based acceptor core through thiophene spacer by mimicking the structure of R. DFT and TD‐DFT have been used to explore the following properties of solar cell material: opto‐electronic properties, reorganization energy, transition density matrix, and open circuit voltage. The designed molecules have side groups triphenylamine (M1), 2‐(5‐(4 [diphenylamino]phenyl) thiophen‐2‐yl) acrylonitrile (M2), 4‐(5‐(ethynylthiophen‐2‐yl)‐N,N‐diphenylaniline (M3), and 4‐(benzo[c][1,2,5]thiadiazol‐4‐yl)‐N,N‐diphenylaniline (M4). Among all the designed molecules, M4 has shown bathochromic shift with λmax 663 nm due to extended conjugation between end‐capped donor units and central electron‐deficient core. Similarly, among all of the designed molecules M4 also shown lower mobility of electron (λe) and hole (λh) which are 0.0047 and 0.0050 eV, respectively, that are also comparable to R. The lower reorganization energy of M4 exhibits the higher transfer of charge among all other designed molecules. Moreover, the open circuit voltage of M4 was 1.56 eV according to that of PC61BM acceptor. Results showed that designed Acceptor‐π spacer‐Donor molecule opened a new pathway for the solar cell material with modified and advanced properties.

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