Turbulence-resistant high-capacity free-space optical communications using OAM mode group multiplexing.

Twisted light carrying orbital angular momentum (OAM), which features a helical phase front, has shown its potential applications in diverse areas, especially in free-space optical (FSO) communications. Multiple orthogonal OAM beams can be utilized to enable high-capacity FSO communication systems. However, for practical OAM-based FSO communication links, atmospheric turbulence will cause serious power fluctuations and inter-model crosstalk between the multiplexed OAM channels, impairing link performance. In this paper, we propose and experimentally demonstrate a novel OAM mode-group multiplexing (OAM-MGM) scheme with transmitter mode diversity to increase system reliability under turbulence. Without adding extra system complexity, an FSO system transmitting two OAM groups with a total of 144 Gbit/s discrete multi-tone (DMT) signal is demonstrated under turbulence strength D/r0 of 1, 2, and 4. In our experiments, the proposed OAM-MGM scheme helps to achieve bit-error-rate (BER) mostly less than 3.8 × 10-3 under turbulence strength D/r0 of 1 and 2 with a total transmitted power of 10 dBm. Compared with the conventional OAM mode multiplexed system, the system interruption probability decreases from 28% to 4% under moderate turbulence strength D/r0 of 2.

Shaping the transmission trajectory of vortex beam by controlling its radial phase.

Vortex beam carrying orbital angular momentum (OAM), which features a helical phase front, has shown its potential applications in diverse areas, especially in free-space optical (FSO) communications. However, when generating vortex beams, the radial phase distribution is usually disregarded in previous reports. In this paper, by controlling the radial phase distribution, we propose a method for the generation of vortex beams with arbitrary convex trajectories. By using this method, we successfully generate vortex beams with different predesigned trajectories with high accuracy. Moreover, we also demonstrate the transmission of the radial phase-controlled vortex beams in FSO links for different scenarios in simulation. Firstly, we generate vortex beams with different OAM states (l=+1, + 3, and +6), which have the same ring diameter at the receiver side. Secondly, we generate three vortex beams (l=+3) with the same ring diameter at different transmission distances (z = 100 m, 200 m, and 300 m). Finally, by carefully controlling the radial phase of the vortex beam, we generate vortex beams that can almost keep the same ring diameter for a long distance. The proposed method for shaping the transmission trajectory of vortex beams may pave the way for more applications in OAM-based FSO communications.

Prognostic values of inflammatory indexes in bevacizumab-treated patients with advanced non-small-cell lung cancer.

Purpose: Inflammatory indexes, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII) and lymphocyte-to-monocyte ratio (LMR), have been confirmed as prognostic factors in multiple manigances. However, the prognostic value of these parameters in bevacizumab-treated non-small-cell lung cancer (NSCLC) is still not clear. Methods: We retrospectively studied 119 patients with advanced NSCLC who received bevacizumab treatment. The associations of pretreatment NLR, PLR, SII and LMR with progression-free survival (PFS) and overall survival (OS) were analyzed. Results & Conclusion: The median PFS and OS of patients with high baseline NLR, PLR and SII and low LMR were significantly decreased than those of patients with low baseline NLR, PLR and SII and high LMR. Multivariable analysis indicated that high baseline SII was independently related with inferior prognosis, and baseline LMR was an independent predictor for OS.

Characterization of BoHV-1 gG-/tk-/gE- Mutant in Differential Protein Expression, Virulence, and Immunity.

Infectious bovine rhinotracheitis (IBR), caused by bovine alphaherpesvirus 1 (BoHV-1), is an important disease affecting cattle worldwide resulting in great economic losses. Marker vaccines are effective in controlling infectious diseases including IBR, because they allow the discrimination between the natural infection and the vaccination. Therefore, a triple gene deleted strain BoHV-1 gG-/tk-/gE- was developed and evaluated in vivo and in vitro as a marker vaccine. In cell culture, this triple mutant virus showed significantly slower growth kinetics and smaller plaques when compared to wild-type (wt) BoHV-1 and double mutant BoHV-1 gG-/tk- (p < 0.01). On proteomic level, it revealed downregulation of some virulence related proteins including thymidine kinase, glycoproteins G, E, I, and K when compared to the wt. In vitro, the triple mutant virus showed a significantly lower and shorter viral shedding period (p < 0.001) in calves compared to double mutant. Moreover, the immunized calves with triple mutant virus showed protection rates of 64.2% and 68.6% against wt BoHV-1 and wt BoHV-5 challenge, respectively, without reactivation of latency after dexamethasone injection. In conclusion, BoHV-1 gG-/tk-/gE- is a safer marker vaccine against IBR although its immunogenicity in calves was decreased when compared to double mutant virus.

Free-space optical communication with quasi-ring Airy vortex beam under limited-size receiving aperture and atmospheric turbulence.

Vortex beams carrying orbital angular momentum (OAM), which feature helical wavefronts, have been regarded as an alternative degree of freedom for free-space optical (FSO) communication systems. However, in practical applications, atmospheric turbulence and limited-size receiving aperture effects will cause OAM modal degradation and seriously reduce the received power. In this paper, by controlling the radial phase distribution of conventional OAM beams, quasi-ring Airy vortex beams (QRAVBs) are successfully generated in the experiments to increase the received power under the limited-size receiving aperture conditions. By employing 72-Gbit/s 16-ary quadrature amplitude modulation (16-QAM) discrete multi-tone (DMT) signals, we successfully demonstrate free-space data transmission with QRAVBs in the experiments. Moreover, the transmission performance of QRAVBs under atmospheric turbulence is also evaluated. Comparing with conventional OAM beam and Bessel beam, the obtained results show that QRAVBs can achieve higher received power and better BER performance under limited-size receiving aperture and atmospheric turbulence conditions.

Experimental demonstration of multiple dimensional coding decoding for image transfer with controllable vortex arrays.

Vortex beams carrying orbital angular momentum (OAM), which featuring helical phase front, have been regarded as an alternative spatial degree of freedom for optical mode coding and multiplexing. For most reported OAM-based mode coding schemes, data information is only encoded by different OAM mode states. In this paper, we introduce a novel design technique to construct vortex array phase grating (VAPGs) for the flexible generation of vortex arrays, and employ the proposed VAPGs to realize multi-dimensional space/mode/amplitude coding/decoding. By designing VAPGs with different parameters and loading them on to a single spatial light modulator (SLM), we successfully generate vortex array with different mode states and relative power in the experiments. Moreover, a 10-bit multi-dimensional space/mode/amplitude data coding/decoding scheme for image transfer in free-space link with a zero bit-error-rate is experimentally demonstrated, which confirm the feasibility of our proposed VAPG-based coding/decoding scheme.

Experimental demonstration of OAM-based transmitter mode diversity data transmission under atmosphere turbulence.

Twisted light carrying orbital angular momentum (OAM), which features helical phase front, has shown its potential applications in diverse areas, especially in optical communications. For OAM-based free-space optical (FSO) links, a significant challenge is the power fading induced by atmospheric turbulence. In this paper, we experimentally demonstrate the mitigation of atmospheric turbulence effects with an OAM-based transmitter mode diversity scheme. By designing multi-OAM phase patterns, we successfully generate multiple OAM modes (OAM-1,0,1, OAM+2,+3,+4, OAM+5,+6,+7) carrying the same data stream for transmitter diversity without adding system complexity. An intensity-modulated direct-detection (IM-DD) system with 39.06 Gbit/s discrete multi-tone (DMT) signal is employed to confirm the feasibility of the OAM-based transmitter mode diversity scheme under atmosphere turbulence. The obtained experimental results show that the received power fluctuation and average bit-error rate (BER) are decreased under moderate to strong turbulence compared to the traditional single OAM mode transmission. In addition, the required transmitted power at 10% interruption probability is relaxed by nearly 2 dB under moderate to strong turbulence.

Financial Self-Efficacy and General Life Satisfaction: The Sequential Mediating Role of High Standards Tendency and Investment Satisfaction.

Important strides have been made toward understanding the relationship between self-efficacy and life satisfaction. However, existing studies have largely focused on work and academic domains, leaving self-efficacy in the finance domain less frequently investigated. The present study applied the self-efficacy construct to the finance domain, namely "financial self-efficacy" (FSE), and tested the sequential mediating roles of high standards tendency and investment satisfaction in the relationship between FSE and general life satisfaction. A total of 323 employees from finance-related businesses completed anonymous questionnaires regarding FSE, high standards tendency, investment satisfaction, and general life satisfaction. Results indicated that FSE influenced general life satisfaction through investment satisfaction, and sequentially through high standards tendency and investment satisfaction. These results provide contributions to the current literature on life satisfaction, and positive psychology literature by shedding light on the roles of high standards tendency and investment satisfaction in the relation between FSE and general life satisfaction.

Expression of AGGF1 and Twist1 in hepatocellular carcinoma and their correlation with vasculogenic mimicry.

BACKGROUND: The most common reason for hepatocellular carcinoma (HCC) treatment failure is recurrence and metastasis. AGGF1 (a promoting gene of tumor metastasis), vasculogenic mimicry (VM, new blood supply formation in malignant tumors), and Twist1 (an evolutionarily conserved basic helix-loop-helix transcription factor) are all valuable factors for metastasis and prognosis in diverse common human cancers. However, the correlation of AGGF1, Twist1, and VM in HCC is still unclear. In this study, we analyzed the correlations among these factors as well as their correlation with clinicopathologic data and survival in HCC. METHODS: Immunohistochemical (IHC) analysis was used to detect the expression of AGGF1 and Twist1 in 111 archival surgical specimens of human HCC. Furthermore, clinical data were collected. RESULTS: Levels of VM, AGGF1 and Twist1 were significantly higher in HCC tissues than in normal hepatic tissues. Levels of VM, AGGF1, and Twist1 were positively associated with AFP, HBsAg, size, capsular invasion, Child-Pugh classification level, and tumor node metastasis (TNM) stage, and negatively associated with patients' overall survival (OS). In multivariate analysis, high levels of VM, AGGF1, Twist1, AFP, Child-Pugh classification level, as well as TNM stage were independently correlated with lower OS in patients with HCC. CONCLUSION: VM and the expression of AGGF1 and Twist1 may represent promising metastatic and prognostic biomarkers, as well as therapeutic targets for HCC.

Prevalence and genetic diversity of bovine viral diarrhea virus in dairy herds of China.

To determine the nationwide prevalence and genetic diversity of bovine viral diarrhea virus (BVDV) in China, 92 dairy farms with more than 500 animals in 19 provinces of China were surveyed in 2017. At each farm, ear notch samples from calves less than six months old and bulk tank milk (BTM) samples were collected. A total of 901 ear notch samples and 329 BTM samples from 183 tanks were sampled. A total of 20 (20/901, 2.22 %) ear notch samples from 10 (10/92, 10.86 %) farms tested positive for BVDV by IDEXX Antigen Point-of-Care (POC) Test kit and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). In addition, 80 of 183 (80/183, 43.7 %) BTM samples from 43 (43/92, 46.7 %) farms were identified as positive by qRT-PCR. The RNA of positive and suspect samples identified by qRT-PCR was subjected to 5'- untranslated region (UTR) amplification by nested RT-PCR and then sequenced. A total of 119 sequences were obtained and phylogenetic analysis of these 5'-UTR sequences revealed the presence of eight different subgenotypes of BVDV-1 including 1a (n = 37, 31.09 %), 1b (n = 5, 4.20 %), 1c (n = 34, 28.57 %), 1d (n = 2, 1.68 %), 1m (n = 25, 21.01 %), 1q (n = 6, 5.04 %), and two unknown subgenotypes which were tentatively typed as "BVDV-1v" (n = 8, 6.72 %) and "BVDV-1w" (n = 2, 1.68 %), respectively. BVDV-1a, 1c, and 1m were the dominant strains, collectively accounting for 80.67 % (96/119) of all sequences. Phylogenetic analysis based on selected N-terminal autoprotease (Npro) sequences confirmed the classification of the 5'-UTR sequences. In conclusion, the prevalence of BVDV persistent infection in dairy cattle was high and genetic diversity was high and increasing, revealing a serious threat to the health of cattle in China and highlighting the need for BVDV control.

Superficial CD34-positive fibroblastic tumor: report of two cases and review of literature.

BACKGROUND: We studied the clinicopathologic features of superficial CD34-positive fibroblastic tumor (SCPFT), which is a newly described neoplasm, to enhance the recognition and diagnostic level of the disease. CASE PRESENTATION: We herein report two cases of superficial CD34-positive fibroblastic tumors in a 33-year-old man and a 30-year-old man. The 33-year-old man presented with a slow-growing subcutaneous nodule 5.0 cm in diameter on the right thigh, and the 30-year-old man developed a painful lump 4.0 cm in diameter on his right thigh. Histologically, the tumor was located in superficial soft tissue with relative circumscription. Tumors had abundant spindled polygonal cells, which were arranged in fascicular or sheet-like patterns. Neoplastic cells were characterized by polymorphic nuclei, granular cytoplasm, intranuclear cytoplasmic pseudoinclusions, and an extremely low mitotic rate. Immunohistochemically, neoplastic cells showed diffuse and strong CD34 expression and focal cytokeratin staining. The expression of S-100 protein, SMA, CD99, H-caldesmon, ALK-1, and bcl-2 were all negative. The Ki-67 index was low. CONCLUSIONS: SCPFT is a rare low-grade fibroblastic tumor that has typical morphologic features and unique biologic behavior. Familiarity with clinicopathologic characteristics of the tumor contributes to the differential diagnosis of similar tumors.

Genetic and phylogenetic analysis of feline calicivirus isolates in China.

The aim of this study was to determine the genetic diversity of Chinese feline calicivirus (FCV) isolates and their phylogenetic relationship with isolates from elsewhere in the world. Phylogenetic analysis was performed based on the partial open reading frame (ORF) 2 sequences (regions B-F) of 21 Chinese FCV isolates and 30 global isolates. The Chinese isolates included 13 isolates from Wuhan, which were isolated in this study, and eight previously published isolates. Sixteen Chinese isolates and two Japanese isolates formed a distinct phylogenetic cluster. Phylogenetic analysis based on the sequences of the complete genome, ORF1, ORF2 and ORF3 of selected isolates supported the above findings. Genogroup analysis revealed that FCV genogroup II is present in China. These findings suggest that Chinese FCV isolates are closely related to Japanese FCV isolates.

A bovine herpesvirus 1 pUL51 deletion mutant shows impaired viral growth in vitro and reduced virulence in rabbits.

Bovine herpesvirus 1 (BoHV-1) UL51 protein (pUL51) is a tegument protein of BoHV-1 whose function is currently unknown. Here, we aimed to illustrate the specific role of pUL51 in virion morphogenesis and its importance in BoHV-1 virulence. To do so, we constructed a BoHV-1 bacterial artificial chromosome (BAC). We used recombinant BAC and transgenic techniques to delete a major part of the UL51 open reading frame. Deletion of pUL51 resulted in severe viral growth defects, as evidenced by lower single and multi-step growth kinetics, reduced plaque size, and the accumulation of non-enveloped capsids in the cytoplasm of infected cells. Using tagged BoHV-1 recombinant viruses, it was determined that the pUL51 protein completely co-localized with the cis-Golgi marker protein GM-130. Taken altogether, pUL51 was demonstrated to play a critical role in BoHV-1 growth and it is involved in viral maturation and egress. Moreover, an in vivo analysis showed that the pUL51 mutant exhibited reduced virulence in rabbits, with no clinical signs, no nasal shedding of the virus, and no detectable serum neutralizing antibodies. Therefore, we conclude that the BoHV-1 pUL51 is indispensable for efficient viral growth in vitro and is essential for virulence in vivo.

Prevalence study and genetic typing of bovine viral diarrhea virus (BVDV) in four bovine species in China.

To determine the nationwide status of persistent BVDV infection in different bovine species in China and compare different test methods, a total of 1379 serum samples from clinical healthy dairy cattle, beef cattle, yaks (Bos grunniens), and water buffalo (Bubalus bubalis) were collected in eight provinces of China from 2010 to 2013. The samples were analyzed using commercial antibody (Ab) and antigen (Ag) detection kits, and RT-PCR based on the 5'-UTR and Npro gene sequencing. Results showed that the overall positive rates for BVDV Ab, Ag and RT-PCR detection were 58.09% (801/1379), 1.39% (14/1010), and 22.64% (146/645), respectively, while the individual positive rates varied among regions, species, and farms. The average Ab-positive rates for dairy cattle, beef cattle, yaks, and water buffalo were 89.49% (298/333), 63.27% (248/392), 45.38% (236/520), and 14.18% (19/134), respectively, while the Ag-positive rates were 0.00% (0/116), 0.77% (3/392), 0.82% (3/368), and 5.97% (8/134), respectively, and the nucleic acid-positive rates detected by RT-PCR were 32.06% (42/131), 13.00% (26/200), 28.89% (52/180), and 19.40% (26/134), respectively. In addition, the RT-PCR products were sequenced and 124 5'-UTR sequences were obtained. Phylogenetic analysis of the 5'-UTR sequences indicated that all of the 124 BVDV-positive samples were BVDV-1 and subtyped into either BVDV-1b (33.06%), BVDV-1m (49.19%), or a new cluster, designated as BVDV-1u (17.74%). Phylogenetic analysis based on Npro sequences confirmed this novel subtype. In conclusion, this study revealed the prevalence of BVDV-1 in bovine species in China and the dominant subtypes. The high proportion of bovines with detectable viral nucleic acids in the sera, even in the presence of high Ab levels, revealed a serious threat to bovine health.

White upconversion luminescence nanocrystals for the simultaneous and selective detection of 2,4,6-trinitrotoluene and 2,4,6-trinitrophenol.

A highly water stable and strong upconversion (UC) luminescence NaYF4@PSI-NH nanosensor for the simultaneous and selective detection of 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP) was successfully developed. Via the 980 nm near-infrared (NIR) irradiation, these nanosensors emit strong white UC luminescence with five typical emission peaks centered at 363, 455, 475, 546, and 654 nm. The UC emission at both 363 and 546 nm was quenched by the addition of TNT; however, the ratio of luminescence intensity at 363 nm to 546 nm (I363/I546) had no change with the increase of TNT concentration. Meanwhile, only violet UC emission at 363 nm was dramatically quenched via the addition of TNP, and the I363/I546 ratio is negatively proportional to the TNP concentration in the range of 0.01-4.5 µg/mL of TNP. On the other hand, the green UC emission intensity at 546 nm is in negative proportion to the concentration of TNT. Moreover, cyclohexane, toluene, and other nitroaromatics (such as 2,4-dinitrotoluene (DNT) and nitrobenzene (NB)) have no influence on the detection. Therefore, we developed a facile method for the simultaneous and selective detection of TNT and TNP in the mixture solution of nitroaromatics independent of complicated instruments and sample pretreatment.

Performance evaluation of a modular detector unit for X-ray computed tomography.

A research prototype CT scanner is currently under development in our lab. One of the key components in this project is the CT detector. This paper describes the design and performance evaluation of the modular CT detector unit for our proposed scanner. It consists of a Photodiode Array Assembly which captures irradiating X-ray photons and converts the energy into electrical current, and a mini Data Acquisition System which performs current integration and converts the analog signal into digital samples. The detector unit can be easily tiled together to form a CT detector. Experiments were conducted to characterize the detector performance both at the single unit level and system level. The noise level, linearity and uniformity of the proposed detector unit were reported and initial imaging studies were also presented which demonstrated the potential application of the proposed detector unit in actual CT scanners.

Multifunctional organic-inorganic composite luminescent nanospheres.

A simple general strategy was successfully developed for the preparation of magnetic-luminescent multifunctional nanocomposites by incorporating fluorescent (pyrene) and magnetic (Fe(3)O(4)) components simultaneously into a poly(styrene-co-methacrylic acid) [poly(St-co-MAA)] copolymer matrix. The nanospheres so prepared were characterized using scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The prepared magnetic-fluorescent inorganic-organic nanocomposites have excellent magnetic and photoluminescent properties. They can be used in magnetic separation of trace amounts of sample, fluorescence detection and imaging applications, including magnetic resonance imaging (MRI) and fluorescence imaging. The fluorescence quenching of the nanospheres in the presence of different amounts of Cu(2+) ions was also investigated. Under optimal experimental conditions, the relative fluorescence intensity of the composite nanosphere colloidal solution is proportional to the concentration of Cu(2+) ions, which indicates that these multifunctional nanocomposites can be used for the magnetic separation and fluorescence detection of Cu(2+) ions.

Attenuation of bovine herpesvirus type 1 by deletion of its glycoprotein G and tk genes and protection against virulent viral challenge.

To develop a novel vaccine against infectious bovine rhinotracheitis (IBR), a bovine herpesvirus-1 (BoHV-1) mutant was constructed by deleting the genes for glycoprotein G (gG) and thymidine kinase (tk) through homologous recombination. The resulting sequences for both genes were shown to be correct and a gG expression defect was also confirmed. A parallel study of the BoHV-1 gG(-)/tk(-), gE(-)/tk(-) mutants and wild type (wt) in 31 calves was performed at three different doses, 4×10(5)PFU, 4×10(6)PFU and 4×10(7)PFU. Compared to wt BoHV-1, inoculation of BoHV-1 gG(-)/tk(-) and gE(-)/tk(-) produced no clinical signs and the virus was not reactivated by dexamethasone (dex). Inoculation of BoHV-1 gG(-)/tk(-) at the doses of 4×10(6) and 4×10(7)PFU provided full clinical protection for the cattle against wt BoHV-1 challenge at 4×10(7)PFU/calf. Although the mutants were associated with significantly lower levels of serum neutralizing antibody, interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) than wt BoHV-1 on days 3, 5 and 7 after immunization, stimulation of IFN-ß by BoHV-1 gG(-)/tk(-) was significantly higher than that of wt BoHV-1 and gE(-)/tk(-) on days 3 and 5. We conclude that BoHV-1 gG(-)/tk(-) was attenuated adequately and that it maintains the ability to stimulate immune protection. Therefore, it may be a promising candidate for a marker vaccine against IBR.