[Open hepatectomy versus laparoscopic in the treatment of primary left-sided hepatolithiasis: a propensity, long-term follow-up analysis at a single center].

To compare short-term and long-term efficacy after laparoscopic left hepatectomy(LLR) to open left hepatectomy(OLH) for primary left-sided hepatolithiasis. Methods: Clinical data of 187 patients with left-sided hepatolithiasis and underwent laparoscopically or open left-sided hepatectomy from October 2014 to October 2019 at the Second Affiliated Hospital of Anhui Medical University were retrospectively analyzed in this propensity score matching (PSM) study and were matched in terms of age, sex, body mass index, liver function, ASA score, comorbidities, history of biliary surgery, and smoking history on the ratio of 1∶1.There were 47 cases in each group and the mean age were (54.7±12.3)years old(range:34 to 75 years old) and (53.2±12.6) years old (range: 34 to 75 years old) in open and laparoscopically group respectively. The data of operation time, intraoperative blood loss, postoperative hospital-stay, complication rate, biliary fistula rate, stone clearance rate, and stone recurrence rate were compared. The quantitative data were compared using t-test or rank-sum test. Count data were analyzed with χ(2) test or Fisher test. Results: No significant difference was observed in the clinical characteristics of included 94 patients in this study(all P>0.05).The length of the postoperative hospital-stay after OLH was significantly higher than that in the LLH group((10.8±3.1) days vs.(8.5±2.2)days, t=4.085, P=0.000). LLR significantly decreased the incidence of postoperative biliary fistula compared with the OLH (6.3% vs.21.2%, χ(2)=4.374, P=0.036) and the rates of postoperative complications in the OLH group was significantly higher than that in the LLH group (48.9% vs.27.6%, χ(2)=4.502, P=0.034). Moreover, the stone recurrence rates in the LLH group was significantly lower than that after OLR (4.2% vs. 17.0%, χ(2)=4.029, P=0.045). OLH (95% CI: 1.55 to 10.75, P=0.004) and postoperative complications (95% CI: 1.29 to 9.52, P=0.013) were independent risk factors for prolonged hospital stay. OLH (95% CI: 1.428 to 44.080, P=0.018) and residual stones (95% CI: 1.580 to 62.379, P=0.014) were independent risk factors for the occurrence of postoperative biliary fistula. Biliary fistula (95% CI: 1.078 to 24.517, P=0.040) was an independent risk factor for the recurrence of stones. Conclusion: Compared with OLH, LLH is safe and effective for the treatment of the primary left-sided hepatolithiasis with the clinical benefits of shorter hospital stay, fewer morbidity and biliary fistula occurrence, and lower stone recurrence rates.

Phylogenetic analysis of HA and NA genes of influenza H1N1 viruses from 1918 to 2017.

The 1918 "Spanish" pandemic is the earliest known influenza H1N1 virus. Since then H1N1 viruses circulated between humans and animals continuously. With the increased amount of samples of H1N1 viruses and technology development, researchers have been studying how the viruses evolved. Here, we analyzed HA and NA genes of H1N1 viruses from three aspects: host distribution, geographical distribution and phylogenetic analysis. The data showed hosts were predominantly human, swine and poultry, and other hosts were mainly cat, ferret, wild bear, canine, cheetah and seal. In terms of geographical distribution, the North America and Eurasia were the main H1N1 influenza pandemic areas. Of them, the United States, China, Japan, Canada, the United Kingdom, India and Singapore were the most affected. The phylogenetic analysis of surface genes of influenza H1N1 viruses from 1918 to 2017 worldwide revealed the distribution of all avian influenza viruses (AIVs) showed a clear geographical difference, mainly concentrated in Eurasia and America. American and Eurasian swine viruses might be the ancestors of the 2009 pandemic virus' HA and NA genes. Swine influenza viruses played an important role in the spread of influenza viruses across species. To our knowledge, this is the first large-scale phylogenetic analysis of HA and NA genes of influenza H1N1 viruses worldwide until now. Our findings further emphasize the importance of surveillance of the genetic diversity of influenza H1N1 viruses in different hosts and raised more concerns about the long-time monitoring. Keywords: influenza H1N1 viruses; HA genes; NA genes; phylogenetic analysis; evolution.

Dual-negative refraction in photonic crystals with hexagonal lattices.

We present a dual-negative refraction effect based on the overlapping bands in a two-dimensional triangular photonic crystal formed by holographic lithography. Under certain conditions, one incident plane wave launched into this photonic crystal can be dispersed into two negative refracted waves at the same frequency and the same perpendicular polarization state with different phase velocities and group velocities. We find that this dual-negative refraction behavior can be easily manipulated by adjusting the incident angle, the frequency of incident wave and the filling ratio of the PhC. This special effect can be applied to realize wave-front division and optical interference in optical holography. Based on this effect, a double focusing imaging phenomenon has been achieved by the PhC slab. These unique features may show great impacts on both fundamental physics and optical device applications.

Anomalous refractive effects in honeycomb lattice photonic crystals formed by holographic lithography.

We have investigated for the first time the anomalous refractive effects of a photonic crystal (PhC) formed by holographic lithography (HL) with triangular rods arranged in a honeycomb lattice in air. Possibilities of left-handed negative refraction and superlens are discussed for the case of TM2 band with the index contrast n = 3.4:1. In contrast to the conventional honeycomb PhC made of regular rods in air, the HL PhCs show left-handed negative refraction over a wider and higher frequency range with high transmissivity (>90%), and the effective indices quite close to -1 for a wide range of incident angles with a larger all-angle left-handed negative refraction (AALNR) frequency range (Deltaomega/omega approximately 14.8%). Calculations and FDTD simulations demonstrate the high-performance negative refraction properties can happen in the holographic structures for a wide filling ratio and can be modulated by changing the filling ratio easily.

Improvement of transmission properties through two-bend resonance by holographic design for a two-dimensional photonic crystal waveguide.

We have investigated the transmission properties of a photonic crystal waveguide (PCW) formed by holographic lithography for the first time with a two-dimensional (2D) triangular holographic photonic crystal (PhC) including a line defect with two 60 masculine bends. Calculations have shown that for this PCW high transmission (>90%) through sharp corners can be obtained in a wide frequency range from 0.298 to 0.310 (omega alpha/2pi c) with the relative band gap of 4% when the dielectric contrast is 7.6:1. As far as we know, this result should be the widest frequency range with high transmission (>90%) in the waveguide of similar 2D triangular PhCs ever reported. We have also found that the specific holographic designs of PhC have strong influence on the resonance between the two waveguide bends, and thus this fact can be used as an effective means to improve the transmission property of 2D holographic PCW. In addition to the simplicity and low cost of holographic fabrication of PhCs, these features may reveal the possibly better guiding ability of holographic PCW than the conventional waveguide and the promising potential of the former in the application of photonic integrated circuits.

Negative refractions in two-dimensional photonic crystals formed by holographic lithography.

We present a study on negative refractions in the four lowest bands of two-dimensional (2D) square lattices formed by holographic lithography (HL) and compare these features with those of a lattice of the same kind but with regular dielectric columns. The plane wave calculations and FDTD simulations have shown that in some bands or for some interfaces the negative refraction can only happen in holographic structures, and generally the rightness of holographic structures and regular structures of the same kind may be different.

Holographic design and band gap evolution of photonic crystals formed with five-beam symmetric umbrella configuration.

We propose a holographic design of five-beam symmetric umbrella configuration, where there are a central beam and four ambient beams symmetrically scattered around the central one with the same apex angle, for fabrication of three-dimensional photonic crystals with tetragonal or cubic symmetries, and systematically analyzed the band gap properties of resultant photonic crystals when the apex angle is continuously increased. Our calculations reveal that large complete photonic band gaps exist in a wide range of apex angle for a relatively low refractive index contrast. Specifically, the face-centered cubic structure with a relative band gap of 25.1% for epsilon = 11.9 can be obtained with this recording geometry conveniently where all the beams are incident from the same half-space. These results will provide us with more understanding of this important recording geometry and give guidelines to its use in experiments.

Holographic design of a two-dimensional photonic crystal of square lattice with pincushion columns and large complete band gaps.

In holographic fabrication of photonic crystals the shape and size of the dielectric columns or particles ("atoms") are determined by the isointensity surfaces of the interference field. Therefore their photonic band gap (PBG) properties are closely related to their fabrication design. As an example, we have investigated the PBGs of a kind of holographically formed two-dimensional (2-D) square lattice with pincushion columns rotated by 45 degrees , and shown that this structure has complete PBGs in a wide range of dielectric contrast comparable to or even larger than those of the same lattice with square columns reported before. The optical design for making this structure is also given. This work may demonstrate the unique feature and advantages of photonic crystals made by holographic method and provide a guideline for their design and experimental fabrication.

[Studies on chemical constitutents from Penthorum chinense Pursh].

OBJECTIVE: To study the chemical constituents of Penthorum chinense. METHOD: Silica gel and macroporous resin were used as adsorbent for isolation and purification. The chemical structures were elucidated by spectral analysis and chemical methods. RESULT: Three compounds were isolated from the water-extract of P. chinense. The structures were identified as 5-hydroxy-flavanone-7-O-beta-D-glucoside (I), 2,4,6-trihydroxybenzoic acid (II) and quercetin(III), respectively. CONCLUSION: Compounds I and II were isolated from this plant for the first time.

Security enhancement of double-random phase encryption by amplitude modulation.

Conventional double-random phase encoding is vulnerable to a chosen or known plaintext attack owing to the linearity of the system. We introduce a technique to break down this linearity with an undercover amplitude modulation in the encryption scheme. As an additional key, this operation can significantly enhance the security of the system. A series of computer simulations have shown the effectiveness of this method and its resistance against the known plaintext attack. The design and parameter choice of the amplitude modulator is also discussed.

Large complete bandgaps in a two-dimensional square photonic crystal with isolated single-atom dielectric rods in air.

It is well known that the square lattice of isolated single-atom dielectric rods in air does not give rise to complete bandgaps even when asymmetry is introduced to lift some degeneracy. However, in this paper, a new kind of two-dimensional square photonic crystal with isolated single-atom dielectric rods in air formed by holographic lithography is proposed, and the relation between their photonic bandgap properties and their specific holographic design are systematically analyzed. In addition to the large complete relative bandgap, namely 9.68% gap/midgap ratio for the dielectric constant contrast of 13.6:1, this structure has very large tolerance on the system parameters and fabrication conditions. This fact can greatly relax the experimental requirements. This work may demonstrate the unique feature and advantages of photonic crystals made by the holographic method and provide a guideline for their design and fabrication.

Simple direct extraction of unknown phase shift and wavefront reconstruction in generalized phase-shifting interferometry: algorithm and experiments.

An algorithm to extract the arbitrary unknown phase shift and then reconstruct the complex object wave in generalized phase-shifting interferometry (GPSI) without the iteration process and measurement of object wave intensity is proposed. This method can be used for GPSI of any frame number >or=2. Both computer simulations with smooth and diffusing object surfaces and optical experiments have verified the effectiveness of this method over a wide range of phase shifts with very satisfactory results.

Fast blind extraction of arbitrary unknown phase shifts by an iterative tangent approach in generalized phase-shifting interferometry.

A novel fast convergent algorithm to extract arbitrary unknown phase shifts in generalized phase-shifting interferometry (PSI) is proposed and verified by a series of computer simulations. In this algorithm an error function is introduced and then the unknown phase shifts are found by an iterative tangent approach. In combination with the statistical method, this algorithm can give the most exact results in the fewest iteration steps. It can be used for generalized PSI of arbitrary frames for both smooth and diffusing objects and can usually reach the exact phase shifts with only four or five iterations for three- or four-frame PSI.

Two-step phase-shifting interferometry and its application in image encryption.

Conventional phase-shifting interferometry (PSI) needs at least three interferograms. A novel algorithm of two-step PSI, with an arbitrary known phase step, by which a complex object field can be reconstructed with only two interferograms is proposed. This algorithm is then applied to an information security system based on double random-phase encoding in the Fresnel domain. The feasibility of this method and its robustness against occlusion and additional noise attacks are verified by computer simulations. This approach can considerably improve the efficiency of data transmission and is very suitable for Internet use.

[Quantitative Chinese pharmaceutical study on children pneumonia treated by Pu fu-zhou].

By method of quantitative Chinese pharmacy, the author studied the children pneumonia cases recorded in two books, "Pu Fuzhou's Medical Cases" and "Pu Fuzhou's Medical Experiences". The rule of Chinese medicine used by Pu Fuzhou was probed preliminarily. It was a characteristic that Pu Fuzhou treated the children pneumonia cases by using Pinelliae Tuber, Exocarpium Citri Rubrum, Jujube and Radix Glycyrrhizae. But the rate of using Herba Lophatherum was less in pneumonia group than in non-pneumonia (contrast) group. According to the rate of overdose prescriptions, 11 Chinese herbal medicines used frequently in pneumonia group were classified into 4 sections. Only overdosage rate of section B (Radix Glycyrrhizae and Peucedanum Decursivum Maxim) was correlated with various kinds of diseases. Referring to the compatibility of dosage of the two Chinese medicines used, there were positive correlation in 35 of 38 pairs, among them, P less than 0.05 in 20; negative correlation in 3 of 38 pairs, among them, P less than 0.05 in 1. It was revealed that in 18 of 38 pairs, in which no significant positive correlation was present, the dosages of Chinese medicine used by Dr. Pu varied with different degree of severity and kind of symptoms he treated.