First report of zucchini tigre mosaic virus infecting four cucurbit crops in China.

Cucurbits including ridge gourd (Luffa acutangula), Chieh-qua (Benincasa hispida Cogn. var. Chieh-qua How), Trichosanthes anguina, and sponge gourd (L. cylindrica) are important vegetables in most Asian countries. The 90 viruses known to infect cucurbits include 15 species in genus Potyvirus. In October 2020, nine cucurbit samples with leaf distortion, blister and mottle were collected from the same field of Foshan City, Guangdong Province, China. All samples were tested by western blot with potyvirus-specific antibody (Agdia lnc., Elkhart, IN) and RT-PCR with potyvirus degenerate primers Sprimer/M4T (Chen et al. 2001). Seven out of nine samples were positive for potyvirus in both tests, including one ridge gourd, one Chieh-qua, one sponge gourd, two bottle gourd (Lagenaria siceraria) and two T. anguina. All PCR products (~700-bp) were cloned and sequenced. Sequences of seven amplicons (OM522614 to OM522618, OP090158 to OP090159) containing partial nib and cp genes shared 80.3-100% nucleotide (nt) identity among themselves, and 81.2-97.7% nt identity with ZTMV isolates from China (MN267689, LC371337, MK988416). Except for one Chieh-qua sample, papaya ringspot virus (PRSV) was detected in the same samples where ZTMV was found through sequencing of the amplicons mentioned above. The obtained sequences (OM808942 to OM808945, OP090170 to OP090171) were 95.4-100% identical with PRSV isolates from China. Further RT-PCR was conducted with ZTMV-specific primers ZTMVdF/ZTMVdR targeting partial P3 and 6K1 genes, and PRSV-specific primers PRSV3778F/PRSV4630R targeting partial P3, full-length 6K1 and partial CI genes for all nine samples. Consistently, seven samples were positive for ZTMV, among which one Chieh-qua sample was infected with only ZTMV and six samples were co-infected with ZTMV and PRSV. Interspecific recombination event has been reported for ZTMV (Peng et al. 2021), to detect the recombinants, RT-PCR was conducted for all nine samples with primers ZTMV600F/ZTMV2400R covering the interspecies recombination site (Peng et al. 2021). A fragment (~1.8 kb) was amplified from one T. anguina sample and sequenced (OP090172), which had 97.0% nt identity with the reported recombinant ZTMV-KF17 (MK988415). To fulfill Koch's postulates, a Chieh-qua sample detected with ZTMV but not PRSV, was used for mechanical inoculation on Chieh-qua seedlings. Blister and leaf distortion similar to the field symptoms were observed 21 days post-inoculation. ZTMV infection was verified by RT-PCR with primer pairs Sprimer/M4T and ZTMVdF/ZTMVdR, respectively, followed by sequencing. No amplicon was detected with primer pairs PRSV3778F/PRSV4630R and ZTMV600F/ZTMV2400R. To study the incidence of ZTMV and PRSV, 33 samples including T. anguina, ridge gourd and Chieh-qua were collected from three different fields in Foshan City in May 2022, and were tested by RT-PCR with ZTMV and PRSV primers aforementioned. 30.3% (10/33) of the samples were positive for ZTMV, 39.4% (13/33) tested positive for PRSV, and 21.2% (7/33) were co-infected with the two viruses. Amplicons of ZTMV (600 bp) from all positive samples were sequenced (OP090160 to OP090169), and were 84.8-85.5% identical with ZTMV-TW (LC371337). Recombinant of ZTMV was detected in one T. anguina with primers mentioned above and was sequenced (OP090173), which had 96.2% nt identity with ZTMV-KF17. To our knowledge, this is the first report of ZTMV infecting ridge gourd, Chieh-qua, T. anguina and sponge gourd. The results implied that ZTMV had a potential risk to more cucurbit crops in the field.

Revisiting the latent structure of negative symptoms in schizophrenia: Evidence from two second-generation clinical assessments.

BACKGROUND: Negative symptoms are core symptom of schizophrenia, and many previous research studied the latent structure of negative symptoms based on a single measurement scale. Applying two second-generation negative symptom scales to the same sample can address measurement-invariance of latent structure. METHODS: Three-hundred-and-five schizophrenia patients were assessed using the CAINS and the BNSS. Confirmatory Factor Analysis (CFA) tested four competing factor-models: (1) a 1-factor model; (2) a 2-factor model comprising the motivation and pleasure (MAP) domain and the diminished expression (EXP) domain; (3) a 5-factor model comprising anhedonia, avolition, asociality, blunted affect and alogia; (4) a hierarchical model comprising the "first-order" 5-domain factors and the "second-order" MAP & EXP factors. RESULTS: The CFA results for the data of the CAINS showed that the 2-factor model had the best data fit over the other competing models. The CFA using the BNSS data in the same sample also supported the superiority of the 2-factor model. Lastly, after combining the items of the BNSS and CAINS together in the same sample for CFA, the 2-factor model prevailed over the other competing models. CONCLUSIONS: The 2-factor model appears to be measurement-invariant latent structure of negative symptoms. The novel method of combining the items of the CAINS and BNSS might have circumvented the possible imperfect construct of a single scale. Our findings support the MAP and EXP factors as the latent structure for negative symptoms.

Towards efficient verifiable multi-keyword search over encrypted data based on blockchain.

Searchable symmetric encryption (SSE) provides an effective way to search encrypted data stored on untrusted servers. When the server is not trusted, it is indispensable to verify the results returned by it. However, the existing SSE schemes either lack fairness in the verification of search results, or do not support the verification of multiple keywords. To address this, we designed a multi-keyword verifiable searchable symmetric encryption scheme based on blockchain, which provides an efficient multi-keyword search and fair verification of search results. We utilized bitmap to build a search index in order to improve search efficiency, and used blockchain to ensure fair verification of search results. The bitmap and hash function are combined to realize lightweight multi-keyword search result verification, compared with the existing verification schemes using public key cryptography primitives, our scheme reduces the verification time and improves the verification efficiency. In addition, our scheme supports the dynamic update of files and realizes the forward security in update. Finally, formal security analysis proves that our scheme is secure against Chosen-Keyword Attacks (CKA), experimental analysis demonstrations that our scheme is efficient and viable in practice.

Research on digital copyright protection based on the hyperledger fabric blockchain network technology.

With the recent development in network technology over a few years, digital works can be easily published online. One of the main issues in the field of digital technology is the infringement of digital works, which can seriously damage the data owners' rights and affects the enthusiasm of the owners to create original work. Thus, more attention is required for the protection of digital copyright as it has a great impact on the development of society. Many digital copyright protection techniques were developed in the past, but still, there are many loopholes in the protection systems to be covered. The protection means are still relatively weak, timeliness is poor, infringement is frequent, a right determination is cumbersome, and the results are not ideal. Aiming at the mentioned problems, this paper proposes a protection technique, which can realize the automatic management of the complete digital rights life cycle on the blockchain using fabric's smart contract technology. The proposed system is based on blockchain technology, which leverages the distributed, tamper-proof and traceable characteristics of blockchain. The system uses smart contracts to manage the full life cycle of digital copyright. The test results show that the proposed system provides effective protection of the digital copyright system and can efficiently confirm the rights of digital copyright.

[Micronuclei induced by chronic inhalation of SO2 in mouse bone marrow cells].

In the chronic inhalation experiment of sulfur dioxide(SO2), micronuclei(MN) frequencies in the polychromatophilic erythroblasts(PCE) of mouse bone marrow and the frequencies of cells with MN were significantly increased in dose-dependent manner. There was a significant difference between the male and the female animals. The results also showed that SO2 inhibited urethone-induced MN formation. These results furtherly confirm that SO2 inhalation was a clastogenic and genotoxic agent to mammalian cells, and the combined effects of SO2 and other mutagens are complex.

Micronuclei induced by sulfur dioxide inhalation in mouse bone-marrow cells in vivo.

Induction effects of sulfur dioxide (SO2) inhalation on micronuclei (MN) formation in the polychromatic erythrocytes (PCE) of mouse bone marrow were studied in vivo. It was shown that SO2 inhalation caused an increase of MN frequencies in the PCE cells in a dose-dependent manner. These results from male and female mice were very similar; no sex difference was observed. These results imply that SO2 is a clastogenic and genotoxic agent.

[Inhalation of sulfur dioxide on the DNA damage of brain cells in mice].

OBJECTIVE: To investigate the inhalation of sulfur dioxide (SO(2)) on the DNA damage of brain cells in mammalian animals. METHOD: Single cell microgel electrophoresis technique (comet test) was used to test the DNA damage of brain cells. RESULTS: (1) After the exposure to SO(2) at 0, 7, 14, 28 mg/m(3), the tail lengths of nuclear DNA in brain cells from male mice were 8.02, 23.14, 46.43 and 53.49 micro m respectively; and that from female mice were 7.23, 12.43, 20.39 and 54.83 micro m respectively. The results showed that: (1) SO(2) inhalation caused damage on DNA of brain cells in a dose-dependent manner; (2) Even under lower concentration of SO(2) as 7 mg SO(2)/m(3), the damage on DNA of brain cells was also reached to 98.8%. It implied that the brain cells of mammalian animals were very sensitive to SO(2) inhalation; (3) The DNA damage of brain cells from male mice is more serious than that from female mice. The reasons remain to be further studied. CONCLUSIONS: SO(2) pollution even at lower concentrations also had a potential risk to the genetic material DNA of brain cells from mammalian animals. The results of our study might explain the recently published epidemiological studies that the workers exposed to SO(2) or SO(2) derivatives had suffered an increase of mortality from brain cancer.