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Summary Many plant viruses with monopartite or bipartite genomes have been developed as efficient expression vectors of foreign recombinant proteins. Nonetheless, due to lack of multiple insertion sites in these plant viruses, it is still a big challenge to simultaneously express multiple foreign proteins in single cells. The genome of Beet necrotic yellow vein virus (BNYVV) offers an attractive system for expression of multiple foreign proteins owning to a multipartite genome composed of five positive‐stranded RNAs. Here, we have established a BNYVV full‐length infectious cDNA clone under the control of the Cauliflower mosaic virus 35S promoter. We further developed a set of BNYVV‐based vectors that permit efficient expression of four recombinant proteins, including some large proteins with lengths up to 880 amino acids in the model plant Nicotiana benthamiana and native host sugar beet plants. These vectors can be used to investigate the subcellular co‐localization of multiple proteins in leaf, root and stem tissues of systemically infected plants. Moreover, the BNYVV‐based vectors were used to deliver NbPDS guide RNAs for genome editing in transgenic plants expressing Cas9, which induced a photobleached phenotype in systemically infected leaves. Collectively, the BNYVV‐based vectors will facilitate genomic research and expression of multiple proteins, in sugar beet and related crop plants.

HIV transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) in resource-limited countries like China where ART has been scaled up and thus leads to an important public health concern. The aim of the study was to elucidate the HIV-1 genetic characteristics and TDR in Hangzhou, China. Two-hundred eleven ART-naive, newly diagnosed individuals were enrolled during January and August 2013. Specimens were classified as recent or chronic infections using the BED capture enzyme immunoassay (BED-CEIA). The pol fragment covering the entire protease and the first 300 codons of the reverse transcriptase gene was amplified by RT-PCR and nested PCR. Genotypic drug resistance (DR) and phylogenetic analysis were performed on the 200 obtained sequences. Multiple genotypes were identified, including CRF01_AE (62.0%), CRF07_BC (31.0%), subtype B (2.0%), CRF08_BC (1.5%), CRF55_01B (1.0%), CRF18_cpx (0.5%), and unique recombinant forms (URFs, 2.0%). All the four URFs were found in men who have sex with men, consisting of a recombination of CRF01_AE with subtype B or CRF07_BC. The prevalence of primary DR in newly diagnosed individuals in Hangzhou was low (4.0%). The proportion of DR mutation to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) was 1.5%, 1.5%, and 1.0%, respectively. BED-CEIA revealed that 21.8% (45/211) of the specimens were associated with recent infections. The prevalence of TDR in recent infections was moderate (6.5%). High HIV diversity and relatively high prevalence of TDR in new infections has been found in Hangzhou, indicating an increasing challenge for future HIV prevention and treatment. J. Med. Virol. 87:1668–1676, 2015. © 2015 Wiley Periodicals, Inc.

We have designed IIR (Infinite Impulse Response) lowpass digital filters based on Butterworth and Chebyshev approximations, and conducted an experiment research of filtering to GT-1A airborne gravity data. The result shows that: by selecting proper parameters such as passband and stopband attenuation, these IIR lowpass digital filters for airborne gravity data can get satisfactory filtering effect almost as good as that of GT-1A filtering result.

In order to quantitatively evaluate the performance index of airborne gravity system, repeated flight lines are usually used to test the coherence of dynamic survey of airborne gravimeter. However, there is no corresponding criterion in the current code to evaluate the quality of repeat line test data of airborne gravity survey. We research and summarize a method of RMS (root mean square) accuracy calculation for the test data of repeat lines. Based on the calculation results of internal and external accord accuracy, we can objectively evaluate the dynamic accuracy index and working status of the instrument.

Gridding of irregularly distributed potential field data is one of the first and most crucial steps in data analysis. This paper brings forward to realize the gridding of potential field data by using inverse interpolation based on the preconditioning conjugate-gradient iterative algorithm. The gridding method adopts Gaussian weighted coefficients as the interpolation operator, Laplacian operator as the smooth filter, and the inverse of the smooth filter as the preconditioning operator. Experimental results on the synthetic model and the raw aeromagnetic data show that the method is suitable for the features of geophysical potential field, and is a computationally efficient and robust 2-D method with high accuracy and perfect effects.

For the first time we point out that the analytic odd points in upper non-source semi-space, where the value cannot be obtained, exist in original forward theoretical expressions of total field ∆T and its gradients of cuboid. Through detailed formula deduction and discussion on the cause why analytic odd points exist, we deduce new forward theoretical expressions of total field T and its gradients of cuboid without analytic odd points in upper non-source semi-space. Comparison of forward calculation of models shows that these new expressions are proved to be correct.