Surface elemental microanalysis with submicron lateral resolution by the laser-ablation laser-induced fluorescence technique

In order to realize surface elemental microanalysis of solid samples with submicron lateral resolution, laser-ablation (LA) combined with high sensitive laser-induced fluorescence (LIF) detection was investigated. A 532 nm or 266 nm nanosecond laser pulse with low pulse energy was used to realize submicron laser-ablation on the surface of a copper alloy, and LIF technique was used to sensitively detect a minor lead element in the ablated samples. ~344 nm and ~267 nm lateral resolutions could be achieved experimentally under 532 nm and 266 nm laser ablations under the current experimental condition, respectively. This demonstrated the feasibility of using a LA-LIF technique for surface elemental microanalysis of solid samples with submicron spatial resolution. The potentials of continually improving the spatial resolution of this technique to nanoscale were discussed.

[Serotype distribution and antimicrobial resistance of Salmonella isolates from retail chicken carcasses in six provinces of China]

Objective: To obtain the serotype diversity and antimicrobial resistance of Salmonella isolates recovered from retail chicken carcasses for sale in six regions of China. Methods: From August 2010 to March 2012, each month 20 retail chicken carcasses including freshly slaughtered, chilled and frozen samples were collected from supermarkets and farmer's markets in 7 monitoring sites in Beijing, Jilin province, Inner Mongolia Autonomous, Shanxi province, Jiangsu province and Guangdong province, respectively. Samples were routinely collected for 12 months for each site. 1 680 chicken carcasses were collected in total and 2 629 Salmonella strains were isolated by PCR and biochemical method. Luminex xMAP method and classical slide agglutination method were carried out to determine isolates' serotypes. Minimal inhibitory concentrations (MICs) of 10 classes of antimicrobials including 14 agents were determined using broth micro-dilution method. Mocular methods were used to determine antimicrobial resistance genes of CIP-CTX-CT co-resistant isolates. Results: In all, 2 629 Salmonella isolates, there were 17 seorgroups and 58 serotypes, B and D1 were the dominant serogroups with rates of 34.7% (n=913) and 31.0% (n=815), Enteritidis (30.8%, n=810), Indiana (17.6%, n=463), Infantis (10.6%, n=278) were the top three serovars. We found 224 CIP-CTX co-resistant S. Indiana containing 3 colistin resistant strains, one of them carrying mcr-1 gene and being ESBLs positive, which demonstrated a nine multi drug resistance against 11 antimicrobials tested. Conclusion: These data began to describe the complicated serovar diversity and heavy antimicrobial resistance of Salmonella isolates recovered from retail chicken carcasses in six regions of China. The findings highlight the emergence of ciprofloxacin and cefotaxime co-resistant S. Indiana and also a mcr-1 positive S. Indiana with heavy multi drug resistance.

[Prognostic value of chemotherapy-induced neutropenia in metastatic colon cancer patients undergoing first-line chemotherapy with FOLFOX]

OBJECTIVE

To evaluate the prognostic value of chemotherapy-induced neutropenia (CIN) in metastatic colon cancer undergoing first-line chemotherapy with FOLFOX.

METHODS

Data were collected from a retrospective survey of 158 consecutive metastatic colon cancer patients who had undergone FOLFOX chemotherapy. The clinicopathological characteristics and chemotherapy features of the patients were analyzed as potential prognostic factors. The patients were stratified by the decreased level of CIN to three groups: large decreased level (the number of neutrophil decreased more than 1.0×10⁹ compared with that before chemotherapy), small decreased level (the number of neutrophil decreased less than 1.0×10⁹ compared with that before chemotherapy) and the absence of neutropenia.

RESULTS

According to a multivariate COX model, decreased level of CIN was a independent prognostic factor of colon cancer patients. Hazard ratios of death were 0.687 (95% CI: 0.381-0.812, P=0.016) for patients with large decreased level of CIN and 0.817 (95% CI: 0.527-0.939, P=0.027) for those with small decreased level of CIN compared with those of absent neutropenia patients. Median overall survival was 12.9 months (95% CI: 10.4-15.4) for patients without neutropenia (A) compared with 20.8 months (95% CI: 18.3-23.1) for patients with large-decreased level of CIN (L) and with 17.3 months (95% CI: 16.2-18.8) for those with small-decreased level of CIN (S vs. L, P=0.018; L vs. A, P=0.009; S vs. A, P=0.011).

CONCLUSION

Our results demonstrate that the decreased level of CIN is a predictor of prognosis in patients with metastatic colon cancer undergoing FOLFOX chemotherapy. Patients who have experienced large decreased level of CIN haave longer survival time than small decreased level of CIN or absent patients. To monitor CIN decreased level timely and adjust chemotherapy drug dose may help improve the prognosis.

[Textual criticism and discrimination on the naming of"Five-abstention Soup of Medical Professional"from the Han-tomb of the Marquis of Haihun]

A lacquer vessel with the inscription of Yi gong wu jin tang (Five-abstention Soup of Medical Profession) has been unearthed from the Han-tomb of Marquis of Haihun, in which"Five abstentions"is related to the incantations and abstention therapies prevalent in the Qin and Han Dynasties. The"Five-abstention Law"is the five rituals and methods during the process of practicing incantations and abstentions therapies including"keeping one's thinking (cun si)","holding the breath(bi qi)","twirling eyes (nian mu)","stepping after Yu's sample (yu bu)"and"incanting and blessing (zhou zhu)". The"Five-abstention Law"uses the medium"soup"to achieve the purpose of treatment."Soup"refers either to"decoction"or to"magic water". The lacquer vessel with the inscription"Five-abstention Soup of Medical professional"could be an instrument for implementing the process of practising the"Five-abstention Law", reflecting the historical facts that Liu He, the Marquis Haihun did accept the incantations and abstention therapies.

[Optic nerve subarachnoid space expansion in MR imaging: a etiology study]

Objective: To investigate spectrum of causes in optic nerve subarachnoid space (ONSS) expansion by using Magnetic Resonance Imaging (MRI). Methods: A retrospective study. Twenty-six patients (46 eyes) with ONSS expansion and 20 healthy adults (40 eyes) were recruited in Neuro-ophthalmology Department of Chinese PLA General Hospital from January, 2014 to December, 2015. The diameters were measured on the optic nerve (OND) and optic nerve sheath (ONSD) 2.4 mm behind the globe. ONSS was calculated by the formula of (ONSD-OND)/2. All participants were under went ophthalmologic examinations. The patients' clinical features, MRI and final diagnosis were analyzed. Qualitative data were compared between groups by using chi square test and quantitative data were compared by independent sample t test. Results: There was no statistically significant difference between ONSS group and control group with age, BMI and mean arterial blood pressure (P>0.05). Larger space was found in ONSS group with mean±standard deviation (SD) of (1.9±0.4) mm comparing to the control group with (1.2±0. 2) mm (t=2.879, P<0.01). Bilateral ONSS expansion were found in 20 patients, 15 patients (75%) with cerebral venous sinus thrombosis (CVST), 2 patients (10%) with neurosyphilis, 2 patients (10%) with peri-neuritis and 1 patient (5%) with hydrocephalus. Unilateral ONSS expansion were seen in 6 patients, 4 patients (66.7%) with compressive lesson on anterior visual pathway, 1 patient (16.7%) with fungal infection and 1 patient (16.7%) with peri-neuritis. Conclusions: The CVST patients more frequently presented bilateral ONSS expansion. Unilateral ONSS expansion may indicate compressive lesions located on the anterior visual pathway. (Chin J Ophthalmol, 2016, 52: 911-917).

Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO_{2}

Here we present a study of magnetism in Co_{0.05}Ti_{0.95}O_{2-δ} anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spectrometry and transmission electron microscopy analyses indicate that a high deposition rate leads to a homogeneous microstructure, while a very low rate or postannealing results in cobalt clustering. Depth resolved low-energy muon spin rotation experiments show that films grown at a low oxygen partial pressure (≈10^{-6}  torr) with a uniform structure are fully magnetic, indicating intrinsic ferromagnetism. First principles calculations identify the beneficial role of low oxygen partial pressure in the realization of uniform carrier-mediated ferromagnetism. This work demonstrates that Co:TiO_{2} is an intrinsic diluted magnetic semiconductor.

Breaking dormancy in freshly matured seeds of Elymus sibiricus, an important forage grass in the Tibetan Plateau

Elymus sibiricus L. is an important forage grass widely distributed in Asia and is usually a dominant species on Tibetan Plateau alpine grasslands. Here, we used the seed development indices of 1000 seed weight, seed moisture content, and seed viability to compare the seed characteristics at 10, 20, 30, 40, 50, and 60 days after anthesis (DAA) in five populations of E. sibiricus growing in Gannan, China. Additionally, seeds collected at 60 DAA were air-dried for one month, and the primary germination percentage (GP) was determined in the laboratory. Treatment of seeds with 0.2% KNO3, 100 mg/L cytokinin, and 500 mg/L GA3 were tested for their effects on dormancy. A primary GP of 16% was found after 12 d of 15/25°C incubation, with no differences among the five populations. The 1000 seed weight and seed viability steadily increased and moisture content continuously fell with DAA. The optimal harvest time for E. sibiricus in an alpine pasture was 50 DAA. No effect on dormancy was found after treating seeds with 0.2% KNO3 or 100 mg/L cytokinin; however, a low concentration of GA3 induced a prompt and synchronized germination. Freshly matured E. sibiricus seeds were classified to be in non-deep physiologically dormant. Treatment of seeds with GA3 before sowing enhanced the emergence speed and seedling uniformity in E. sibiricus.

Mapping quantitative trait loci for nitrogen uptake and utilization efficiency in rice (Oryza sativa L.) at different nitrogen fertilizer levels

Genetic improvement is the fundamental basis for improving nitrogen-use efficiency. A better understanding of genetic factors controlling nitrogen uptake and utilization is required for crop genetic improvement. In this study, we identified the quantitative trait loci (QTLs) associated with traits of nitrogen uptake and utilization by using the single-sequence repeat marker method and a recombinant inbred line (RIL) population derived from a super hybrid Xieyou9308. All the traits investigated were inherited quantitatively by continuous variation and showed normal distribution in phenotype with transgressive segregation in the RIL population. Most of the traits were significantly correlated with each other except for nitrogen absorption ability (NAA) with nitrogen harvest index (NHI) and NHI with agricultural nitrogen-absorption efficiency (ANAE). At logarithmic odds value of 2.3, total 13 candidate QTLs, including 4 for NAA, 2 for NHI, 2 for physiological nitrogen-use efficiency, 1 for agricultural nitrogen-use efficiency (ANUE), and 4 for ANAE, were detected and mapped on chromosomes 2, 3, 4, 5, 8, 9, 10, and 12. Significant pleiotropic effect or neighboring expression of QTLs was observed among traits. At position 64.8 cM on chromosome 4 near the marker RM5757, there was a QTL cluster of NAA, ANUE, and ANAE, and at chromosome 5 near the marker RM5968, there was a QTL cluster of NAA and ANUE. The QTL clusters might provide partial explanation and genetic mechanism for the observed correlations between nitrogen uptake and utilization efficiency traits and might form a basis for future breeding programs.

Influence of surgical resection of hepatocellular carcinoma(HCC) for hematogenous dissemination of HCC cells and its effect on recurrence and metastasis: 3 years prospective study

Aims was to study whether hepatal surgery leads to hematogenous dissemination of hepatocellular carcinoma (HCC) cells and determine period of its persistence by nested reverse transcription-polymerase chain reaction (RT-PCR). Peripheral vein blood (5ml) samples were obtained from 54 HCC patients of T1N0M0 and 6 HCC patients of T2N0M0 stage and 20 patients with liver cavernous hemangioma(LCH) before operation and 48h,72h and 1 week after surgical resection of hepatoma between Janurary 1st, 2007 and December 31th, 2010. We detected alpha-fetoprotein (AFP) messenger RNA(mRNA) by nested RT-PCR perioperatively.FPmRNA of all 60 cases of HCC patients and 20 cases of LCH were negative before hepatal surgery, 28 of 60 HCC cases became positve at 48h after surgery (46.7%), 16 of 60 HCC cases remained positive at 72h postoperatively(26.7%), none of 60 HCC patients AFPmRNA was detected at 1 week after hepatal surgery(0.0%). None of LCH patients were detected AFPmRNA after hepatal surgery(0.0%). For 28 HCC patients with AFPmRNA positive after hepatal surgery, 4 HCC patients developed intrahepatic tumor recurrences in 1st year (4/28, 14.3%),6 HCC patients relapsed in the second year(6/28,21.4%),10 HCC patients relapsed in the third year(10/28,35.7%). For 32 HCC patients with AFPmRNA negative group postoperation, 5 cases relapsed in 1st year (5/32, 15.6%),7 cases developed intrahepatic tumor recurrences in the second year (7/32, 21.9%),11 cases relasped in the third year (11/32, 34.4%,P>0.05),none of HCC patients occured distal metastasis after surgical resection of hepatoma. None of LCH patients relapsed postoperation within three years.Hepatal surgery may cause HCC cells spreading into peripheral blood shortly, but it may be not concerning with recurrence or metastasis of HCC.

Utilizing acid mine drainage sludge and coal fly ash for phosphate removal from dairy wastewater

This study aims to investigate a new and sustainable approach for the reuse of industrial by-products from wastewater treatment. The dairy industry produces huge volumes of wastewater, characterized by high levels of phosphate that can result in eutrophication and degradation of aquatic ecosystems. This study evaluated the application of acid mine drainage (AMD) sludge, coal fly ash, and lignite as low-cost adsorbents for the removal of phosphate from dairy wastewater. Material characterization using X-ray fluorescence, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis revealed significant amounts of crystalline/amorphous Fe/Al/Si/Ca-based minerals and large surface areas of AMD sludge and fly ash. Batch adsorption isotherms were best described using the Freundlich model. The Freundlich distribution coefficients were 13.7 mg(0.577) L(0.423) g(-1) and 16.9 mg(0.478) L(0.522) g(-1) for AMD sludge and fly ash, respectively, and the nonlinearity constants suggested favourable adsorption for column applications. The breakthrough curves of fixed-bed columns, containing greater than 10 wt% of the waste materials (individual or composite blends) mixed with sand, indicated that phosphate breakthrough did not occur within 100 pore volumes while the cumulative removal was 522 and 490 mg kg(-1) at 10 wt% AMD sludge and 10 wt% fly ash, respectively. By contrast, lignite exhibited negligible phosphate adsorption, possibly due to small amounts of inorganic minerals suitable for phosphate complexation and limited surface area. The results suggest that both AMD sludge and fly ash were potentially effective adsorbents if employed individually at a ratio of 10 wt% or above for column application.

p53 mediates autophagy activation and mitochondria dysfunction in kainic acid-induced excitotoxicity in primary striatal neurons

The present study sought to investigate if p53 mediates autophagy activation and mitochondria dysfunction in primary striatal neurons in kainic acid (KA)-induced excitotoxicity. The excitotoxic model of primary striatal neurons was established with KA. The levels of p53, microtubule-associated protein 1 light chain 3 (LC3), Beclin1, and p62 were examined by Western blot and immunostaining. Autophagy activation was also determined with electron microscope. To evaluate the contribution of p53 to autophagy activation and mitochondria dysfunction in KA-induced excitotoxicity, the protein levels of LC3, Beclin1, and p62, the mitochondrial transmembrane potential and the mitochondrial Reactive oxygen species (ROS) after pretreatment with the p53 inhibitor pifithrin-alpha (PFT-α) and the autophagy inhibitor 3-methyladenine (3-MA) were analyzed. Excitotoxic neuronal injury was induced after KA treatment as demonstrated by increases in lactate dehydrogenase (LDH) leakage and was significantly inhibited by PFT-α. Western blot and immunostaining showed that the induction of p53 protein occurred in the cytosol and the nucleus. Increases in autophagic proteins LC3 and Beclin1 were observed, whereas the protein levels of p62 decreased after KA treatment. Electron microscope analysis showed increased autophagosomes in the cytoplasm. The changes in LC3, Beclin1, and p62 levels were blocked by PFT-α, PFT-μ, 3-MA, and E64d but not Z-DEVD-FMK. JC-1 staining showed the depolarization of mitochondrial membrane potential after excitotoxic insult. Mito-tracker and RedoxSensor Red CC-1 staining showed an increased production of mitochondrial ROS after excitotoxic insult. These effects were significantly suppressed after pretreatment with PFT-α and 3-MA. This study suggests that p53 mediates KA-induced autophagy activation and mitochondrial dysfunction in striatal neurons.

Degradation of 2,4,5-trichlorophenoxyacetic acid by a novel Electro-Fe(II)/Oxone process using iron sheet as the sacrificial anode

A novel electrochemically enhanced advanced oxidation process for the destruction of organic contaminants in aqueous solution is reported in this study. The process involves the use of an iron (Fe) sheet as sacrificial anode and a graphite bar as cathode. In the oxidation process, once an electric current is applied between the anode and the cathode, a predetermined amount of Oxone is added to the reactor. Ferrous ions generated from the sacrificed Fe anode mediate the generation of highly powerful radicals (SO(4)(•-)) through the decomposition of Oxone. The coupled process of Fe(II)/Oxone and electrochemical treatment (Electro-Fe(II)/Oxone) was evaluated in terms of 2,4,5-Trichlorophenoxyacetic acid degradation in aqueous solution. Various parameters were investigated to optimize the process, including applied current, electrolyte and Oxone concentration. In addition, low solution pH facilitates the system performance due to the dual effects of weak Fenton reagent generation and persulfate ions generation, whereas the system performance was inhibited at basic pH levels through non-radical self-dissociation of Oxone and the formation of ferric hydroxide precipitates. Furthermore, the active radicals involved in the Electro-Fe(II)/Oxone process were also identified. The Electro-Fe(II)/Oxone process demonstrates a very high 2,4,5-T degradation efficiency (over 90% decay within 10 min), which justifies the novel Electro-Fe(II)/Oxone a promising treatment process for herbicide removal in water.

Trends and perioperative outcomes of inpatient antireflux surgery in the United States, 1993-2006

Antireflux surgery is an effective treatment for gastroesophageal reflux disease, but postoperation complications and durability may be problematic. The objective of the study was to determine whether inpatient antireflux surgery continued to decline in the United States due to concerns about its long-term effectiveness and the popularity of gastric bypass surgery and to assess recent changes in its perioperative outcomes. Using the Nationwide Inpatient Sample, we identified adult patients undergoing inpatient antireflux surgery during 1993-2006 and compared the trends of inpatient antireflux surgery with inpatient gastric bypass surgery. Perioperative complications included laceration, splenectomy, transfusion, esophageal dilation, total parenteral nutrition, and infection. Inpatient antireflux surgery increased from 9173 in 1993 to 32 980 in 2000 (+260%) but then decreased to 19 668 in 2006 (-40%). Compared with 2000, patients undergoing inpatient antireflux surgery in 2006 were older (49.9 ± 32.4 vs. 54.6 ± 33.6 years) and had a longer length of stay (3.1 ± 10.0 vs. 3.7 ± 13.4 days), more complications (4.7% vs. 6.1%), and higher mortality (0.26% vs. 0.54%) (all P < 0.05). Compared with inpatient gastric bypass surgery, length of stay was longer and mortality was higher for inpatient antireflux surgery in 2006, but neither was significant controlling for age. In 2006, perioperative outcomes of inpatient antireflux surgery were better in high-volume hospitals (all P < 0.01). Inpatient antireflux surgery continued to decline in the United States from 2000 to 2006, concomitant with a dramatic increase in inpatient gastric bypass surgery. Older patient age and worsening perioperative outcomes for inpatient antireflux surgery suggest increased medical complexity and possibly a larger share of reoperations over time. Designating centers of excellence for antireflux surgery based on local expertise may improve outcomes.

Degradation of a xanthene dye by Fe(II)-mediated activation of Oxone process

A powerful oxidation process using sulfate radicals activated by transition metal mediated Oxone process has been evaluated in depth by monitoring the degradation of a xanthene dye Rhodamine B (RhB) in aqueous solution. Ferrous ion was chosen as the transition metal due to its potential catalytic effect and wide availability in dyeing industrial effluent. The effects of parameters including reactant dosing sequence, Fe(II)/Oxone molar ratio and concentration, solution pH, and inorganic salts on the process performance have been investigated. Total RhB removal was obtained within 90 min under an optimal Fe(II)/Oxone molar ratio of 1:1. The RhB degradation was found to be a two-stage kinetics, consisting of a rapid initial decay and followed by a retarded stage. Additionally, experimental results indicated that the presence of certain anions had either a positive or negative effect on the process. The inhibitory effect in the presence of SO(4)(2-) was elucidated by a proposed formula using Nernst equation. Furthermore, dye mineralization in terms of TOC removal indicates that stepwise addition of Fe(II) and Oxone can significantly improve the process performance by about 20%, and the retention time required can be greatly reduced comparing with the conventional one-off dosing method.

Cytotoxic chaetoglobosins from the endophyte Chaetomium globosum

Two new alkaloids chaetoglobosins V (1) and W (2), together with the six known congeners 3-8, were isolated through bioassay-guided fractionations from the EtOAc extract of a solid culture of Chaetomium globosum IFB-E041. The structures were elucidated by spectroscopic methods including mainly 1D and 2D NMR techniques. Chaetoglobosin W (2) was unique in its possession of an oxolane ring formed via an oxygen bridge between C-3 and C-6. The isolated fungal metabolites exhibited moderate cytotoxic activities against four human cancer cell lines (KB, K562, MCF-7, and HepG2) with their IC(50) values in a range of 18-30 µg/mL.

Wavefront reconstruction and three-dimensional shape measurement by two-step dc-term-suppressed phase-shifted intensities

A wavefront reconstruction and three-dimensional (3-D) shape measurement method by a two-step phase-shifting algorithm with arbitrary phase shift in (0,pi) is proposed. In this method, only two phase-shifted intensities, with the removal of the dc term by an averaging technique in spatial domain or low-pass filter operation in the frequency domain, are needed, and the other additional measurements are no longer required. The simulation for an irregular wavefront has shown the feasibility, and the optical experiment for a 3-D face mask in the case of a sinusoidal fringe projection system has illustrated the validity of the proposed method.

Cytotoxicity and phytotoxicity of trichothecene macrolides from Myrothecium gramminum

(1)H-NMR guided fractionation of the EtOAc extract from the culture of Myrothecium gramminum (strain no. 3.1968) led to the isolation of eight cytotoxic trichothecene macrolides ( 1 - 8), all being substantially inhibitory against HepG2 (human hepatocellular carcinoma) and KB (human nasopharynyeal epidermoid tumor) cell lines with IC (50) values ranging from 2.2 to 12.2 mug/mL. Their inactivity to or weaker action on Vero cells (IC (50) values > 20 microg/mL, originated from the African green monkey kidney) highlighted preliminarily the nature of the selective cytotoxicity of the fungal metabolites against the test cancer cell lines. In addition, verrucarin A ( 1) and roridin A ( 5) were found to be potent inhibitors of the radial growth of Echinochloa crusgalli with corresponding IC (50) values of (7.96 +/- 0.31) x 10 ( - 6) and (9.18 +/- 0.44) x 10 ( - 6) M, respectively, which were more potent than that of the positive control (2,4-dichlorophenoxyacetic acid) [(9.40 +/- 0.04) x 10 ( - 5) M].

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.

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.

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.

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.