Parallel structured optical fiber in-line Fabry-Perot interferometers for high temperature sensing

We propose and demonstrate parallel structured optical fiber in-line Fabry-Perot interferometers for high temperature sensing. The device consists of three Fabry-Perot cavities in parallel connection, which allows three independent fringe patterns superimposed at its output, and, as a result, a number of dominant fringe peaks/dips appear, thus enabling unambiguous measurement in a large range. The device is featured with compact size, robust structure, and excellent high temperature sustainability, which makes it promising in extreme environment monitoring.

Multiresidue Gas Chromatographic Method for Determining Synthetic Pyrethroid Pesticides in Agricultural Products: Collaborative Study

Fourteen laboratories from 6 countries and regions participated in an international collaborative study to evaluate a multiresidue gas chromatographic (GC) method for determining 8 synthetic pyrethroid pesticides in grains, fruits, and vegetables. The study design was based on Youden’s matched-pairs principle for collaborative tests of analytical methods. Each laboratory analyzed 12 collaborative samples of wheat, oranges, and tomatoes as blind samples. Wheat samples were extracted with acetonitrile–water (2 + 1), while orange and tomato samples were extracted with acetone. Residues were partitioned into hexane, evaporated to dryness with a rotary evaporator, and then dissolved in hexane. The hexane extract was partitioned with acetonitrile and cleaned up on a 5% water-deactivated Florisil column with 6% ethyl ether in hexane as eluant. Residue concentrations were determined by GC with electron capture detection with split-less injection by comparison with single-point calibration standards. The appropriate standard concentration was determined by screening sample extracts before analysis. The multiresidue method was tested over the concentration range of 0.0951.909 mg/kg depending on the 8 different of pesticides and agricultural products analyzed in the collaborative study. Statistical analysis of data from 13 laboratories showed weighted average recoveries for 8 pyrethroids in wheat, oranges, and tomatoes at 0.105–1.909,0.095–1.909, and 0.105–0.954 mg/kg, respectively, ranging from 91.8 to 100.2%, from 88.1 to 100.6%, and from 88.2 to 101.5%, respectively. Reproducibility relative standard deviation values ranged from 6.46 to 17.74%, from 5.94 to 18.13%, and from 5.59 to 10.48%, respectively. Repeatability relative standard deviation values ranged from 6.34 to 10.84%, from 5.19 to 11.72%, and from 3.20 to 8.09%, respectively. The multiresidue GC method for determining synthetic pyrethroid pesticides in agricultural products has been adopted first action by AOAC INTERNATIONAL.

Cascaded multiple Fabry-Perot interferometers fabricated in no-core fiber with a waveguide for high-temperature sensing

An optical fiber high-temperature sensor is proposed and demonstrated by use of cascaded multiple Fabry-Perot interferometers in no-core fiber with a waveguide fabricated by femtosecond laser pulse inscription. The device can sustain the high temperature up to 1100°C, and the temperature sensitivity obtained is 8.9 pm/°C within the temperature range 100°C-400°C, and 16.36 pm/°C within the temperature range 400°C-1100°C, respectively. Such a no-core fiber-based device can be fabricated in a simple way and operated reliably, which makes it attractive for extreme environment monitoring.

Highly sensitive PDMS-filled Fabry-Perot interferometer temperature sensor based on the Vernier effect

A highly sensitive temperature sensor is demonstrated experimentally, which is fabricated based on a Fabry-Perot interferometer (FPI) filled with polydimethylsiloxane (PDMS). The sensor's sensitivity is -0.653  nm/°C by utilizing the thermal expansion effect of PDMS, which has been greatly improved compared to that of the traditional FPI temperature sensor. Moreover, in order to further improve the sensitivity, a scheme where two parallel FPI structures are used to form the Vernier effect is proposed, which are a sensing FPI and reference FPI, respectively. Such a temperature sensor based on the FPI filled with PDMS and the Vernier effect exhibits a high temperature sensitivity of 17.758 nm/°C. Meanwhile, the proposed sensors show the advantages of high sensitivity, simplicity, and low cost.

[Congenital microtia with aural atresia or stenosis accompany with first branchial cleft anomaly: report of 5 cases]

Objective: To summarize the experience of the diagnosis, treatment and effects of the cases with coexistence of first branchial cleft anomaly(FBCA) and microtia with congenital aural atresia or stenosis(external auditory canal stenosis, EACS). Method: This was a retrospective study. The clinical data of 5 patients with microtia and EACS in Beijing Tongren Hospital of Capital Medical University from October 2015 to March 2018 were collected, including 3 males and 2 females, aged from 5 to 28 years. The clinical characteristics, imaging findings, treatment methods and effects of 5 patients were analyzed. Result: The 5 cases were all coexistence of EACS and FBCA, three of who associated with cholesteatoma of external auditory canal. CT showed external auditory canal stenosis with soft tissue shadow, sometimes gas or bone septum found inside, filling in the external auditory canal, combined with canal bone destruction irregularly. All patients underwent surgical resection of FBCA, 3 patients accompanied by cholesteatoma resection and canalplasty. The postoperative follow-up ranged from 10 to 39 months, and no recurrence of infection was observed. Conclusions: EACS and FBCA both result from maldevelopment of the first branchial cleft. These two malformations, FBCA and EACS with or without cholesteatoma, can occur simultaneously, in which situation CT shows external auditory canal stenosis with soft tissue shadow inside. These patients underwent surgical resection of FBCA combined with cholesteatoma resection with good result.

[Establishment and evaluation of a triple-color human papillomavirus pseudovirion neutralization assay]

Objective: To establish a triple-color pseudovirion-based neutralization assay (PBNA) and evaluate its capability of detecting immunogenicity of the sera generated by the immunization of HPV 9-valent vaccine. Methods: HPV pseudovirus (PsVs) 6/11/16/18/31/33/45/52/58 with the encapsidated fluorescence expressing red fluorescent plasmid N31-MCHREEY, green fluorescent N31-EGFP or blue fluorescent N31-mTagBFP were generated. The concentration of HPV PsVs and the infection titers of HPV PsVs were detected by double-antibody sandwich ELISA and TCID(50), respectively. The single- and triple color HPV 16/33/45 PsVs were used to detect the neutralization titers of mice sera immunized with HPV 9-valent vaccine and confirmed the accuracy and specificity of the triple-color PBNAs. Then, the single- and triple color HPV 6/11/18/31/33/45/52/58 PsVs were employed to detect the neutralization titers of cynomolgus macaques sera immunized with HPV 9-valent vaccine and determined whether the triple-color PBNAs could be applied to evaluate the immunogenicity of the sera generated by the immunization of HPV9-valent vaccine. Results: The concentration of HPV16 PsVs encapsulating green, red or blue fluorescent plasmid was 5.0 to 6.0 μg/ml and HPV6/11/18/31/33/45/52/59 triple-color HPV PsVs was about 1.0 to 3.0 μg/ml. 9 types HPV PsVs containing EGFP, Mcherry or mTagBFP reporter plasmid were obtained and the concentration can meet the need of neutralization detection. 9 types single-color fluorescent HPV PsVs had similar infectivity against 293FT cells with the infection titer values between 1×10(4) and 1×10(5). The results of PBNAs showed that there was no significant difference in the anti-HPV neutralization titers of mice sera induced by HPV 9-valent vaccine between single-color and triple-color HPV16/33/45 PsVs (P>0.05). Similarly, there was also no significant difference in the anti-HPV neutralization titers of cynomolgus macaques sera induced by HPV 9-valent vaccine between single-color and triple-color HPV6/11/18/31/33/45/52/58 PsVs (P>0.05). Conclusion: We successfully established the triple-color PBNAs and verified the accuracy and specificity of triple-color PBNAs consistent with single-color PBNAs. The triple-color PBNAs can be applied to evaluate the immunogenicity of HPV 9-valent vaccine's immune serum.

Construction of cascaded Fabry-Perot interferometers by four in-fiber mirrors for high-temperature sensing

An optical fiber high-temperature sensor is proposed and demonstrated by use of cascaded Fabry-Perot interferometers based on four in-fiber mirrors fabricated by femtosecond laser inscription. The output fringe pattern of the device exhibits dominant/highly distinguishable dip wavelength, which helps in unambiguous measurement beyond the free spectral range. The device has excellent thermal stability in high temperature up to 1100°C, and the temperature sensitivity obtained is 9.91 pm/°C within the temperature range of 100°C to 400°C, and 15.88 pm/°C within the temperature range of 400°C to 1100°C, respectively. The device features compact size, simple fabrication, and convenient operation, which make it attractive for monitoring of extreme environment.

In-line reflective Mach-Zehnder interferometer based on a tilted in-fiber beam splitter

A fiber in-line reflective Mach-Zehnder interferometer is proposed and experimentally demonstrated, which is based on a tilted in-fiber beam splitter inscribed by a femtosecond laser. The beam splitter splits the incident light beam into two parts; one is directed to the fiber cladding-air interface, where it experiences total internal reflection and is directed to the fiber core. The other part of the light beam keeps traveling in the fiber core. The two parts of the light beams are recombined in the fiber core to generate interference before being reflected at the fiber cut end face. The device proposed is compact in size, robust in mechanical strength, easy in fabrication, and can be used for environmental refractive index sensing in a convenient manner.

Generation of pulse-width controllable dissipative solitons and bound solitons by using an all fiber saturable absorber

A passively mode-locked fiber laser with controllable pulse width is demonstrated by use of an all-fiber saturable absorber based on a hybrid no-core fiber (NCF)-graded index multimode fiber (GIMF) structure incorporated into an Er-doped fiber ring cavity. Such a hybrid NCF-GIMF structure has a tunable intracavity filtering effect. As a result, the mode-locking operation is achieved with controllable pulse width and spectral bandwidth in the normal dispersion regime by only stretching the fiber device. Soliton pulses with the pulse width of 7.7-23 ps are generated, and bound solitons with variable widths are also experimentally demonstrated. The results obtained reveal the versatility and flexibility of the NCF-GIMF structured device in controlling the pulse dynamics for different experimental requirements.

Hollow-Core-Photonic-Crystal-Fiber-Based Miniaturized Sensor for the Detection of Aggregation-Induced-Emission Molecules

A miniature sensor for detection of aggregation-induced-emission (AIE) molecules is proposed in this work. The sensing head is fabricated by use of hollow-core photonic crystal fiber with a core diameter of about 4.8 μm. The cladding holes are sealed with a fusion splicing technique, and the central hole remains open to allow the filtration of solution with AIE molecules. When the solution is excited by an ultraviolet lamp, the fluorescence is received by a fiber-optic spectrometer. The fluorescence intensity is associated with the concentration of AIE molecules and the infiltrated-core length. In the whole process of the experiments, the output-peak wavelength is stable, which indicates that the existing forms of AIE particles are stable, and the fluorescence reabsorption can be neglected. The experimental results obtained are in accordance with traditional microplate-spectrophotometer methods. The most exciting result is that the amount of sample measured can be as low as 0.36 nL, which allows the detection of AIE molecules at only 0.02 pmol. In addition, the miniature sensor was successfully applied to the detection of an AIE-based bioprobe for evaluating the activity of the dipeptidyl-peptidase 4 (DPP-4) inhibitor sitagliptin with an IC₅₀ of 59.80 ± 3.06 nM. The advantages of small device size and nanoliter-scale sample volumes suggest that the proposed sensor is promising for many biosensing applications.

Whispering-gallery-mode excitation in a microsphere by use of an etched cavity on a multimode fiber end

In this Letter, we demonstrate a whispering-gallery-mode (WGM) microsphere resonator. The device is fabricated by fusion splicing a section of no-core fiber with multimode fiber (MMF) and single-mode fiber at its two ends. The open end of the MMF is etched to create an arc-shaped cavity, with a microsphere glued at its bottom. When the arc of the cavity bottom and microsphere surface are tangent, part of the incident light is coupled into the microsphere and travels exactly one circle before being directed back to the MMF core along the tangent line and exciting the WGM. The device has a Q-factor of 1.21×10⁴, and is robust in structure and low in cost.

In-fiber beam splitters for construction of in-line Michelson interferometers

We demonstrate optical fiber in-line Michelson interferometers based on two in-fiber beam splitters crossing the core of a single-mode fiber, fabricated by a femtosecond laser. The in-fiber beam splitter reflects part of the incident light to the air-cladding interface before being reflected back while passing the rest to travel along the fiber core. The two in-fiber beam splitters, air-cladding interfaces, and the cutting fiber end face together form a combined three in-line Michelson interferometers. This Michelson interferometer device is robust in mechanical strength, easy in fabrication, compact in size, and low in cost.

Femtosecond laser inscribed straight waveguide in no-core fiber for in-line Mach-Zehnder interferometer construction

A new fiber in-line Mach-Zehnder interferometer based on a straight waveguide along the central axis of the no-core fiber sandwiched between single mode fibers is fabricated by a femtosecond laser. The device can be used for high temperature sensing with a sensitivity of -278.86  pm/°C and for bending sensing with a sensitivity of 0.28  nm/m^-1. The high mechanical strength, simple fabrication, and precisely controlled free spectral range make the device attractive for potential applications in high temperature monitoring.

[The relationship between core members' individual social capital and performance among HIV/AIDS related community-based organization]

Objective: To investigate the relationship between core members' social capital and performance among HIV/AIDS-related community-based organizations (CBO). Methods: From July to December in 2015, a total of 327 core members from 212 HIV/AIDS-related CBO in 8 provinces were recruited based on the prevalence of HIV/AIDS (e.g., Yunnan, Hunan, and Sichuan are in high epidemic level; Anhui, Hubei, Shandong, and Jilin are in middle epidemic level; and Gansu is in low epidemic level) by multistage stratified cluster sampling and convenient sampling method. A questionnaire was administered in this study, including general demographic information, core members' social capital, individual performance and organizational performance. Multivariate logistic regression model was used to analyze the relationship between core members' social capital and performance among CBO. Results: Among the 327 individuals, the proportion of male was 201(61.47%). The proportion of core members from grassroots CBO was 66.97% (219/327). Core members from non-grassroots organizations were more likely to publish articles, the OR (95%CI) was 2.58 (1.30-5.14); Social network had a positive impact on the AIDS experts, the OR (95%CI) was 2.41(1.47-3.95); Core members from registered CBO were more likely to secure funding for the organization, the OR (95%CI) was 3.42 (1.65-7.10); Social network and the core members from high endemic areas were significantly correlated with the number of HIV/AIDS patients, the OR (95%CI) were 2.79 (1.27-6.14) and 1.99 (1.21-3.27). Conclusions: We should use the core members' social network to establish relationship and communication with organizations and institutions, ultimately accelerating the growth of HIV/AIDS prevention and care.

Stretched graded-index multimode optical fiber as a saturable absorber for erbium-doped fiber laser mode locking

A novel mode-locking method based on the nonlinear multimode interference in the stretched graded-index multimode optical fiber (GIMF) is proposed in this Letter. The simple device geometry, where the light is coupled in and out of the stretched GIMF via single-mode fibers, is demonstrated to exhibit the temporal intensity discrimination required for mode locking. The nonlinear saturable absorber (SA) characteristics of the device are controllable by simply adjusting the strength of the stretching applied. The modulation depth of the device, which consists of ∼23.5  cm GIMF, is tuned from 10.37% to 22.27%. Such a simple SA enables the wavelength-switchable mode-locking operation in a ring Er-doped fiber laser, and ultrafast pulses with a pulse width of 506 fs at 1572.5 nm and 416 fs at 1591.4 nm were generated. The versatility and simplicity of the SA device, together with the possibility of scaling the pulse energy, make it highly attractive in ultrafast photonics.

Fiber in-line Mach-Zehnder interferometer based on a pair of short sections of waveguide

A fiber in-line Mach-Zehnder interferometer based on a pair of femtosecond laser inscribed short sections of waveguide is presented. One short waveguide directs part of the propagating light from the fiber core to the cladding-air interface, and experiences multiple total internal reflections before taking back to the fiber core by the other short waveguide. The device is robust in structure, can be fabricated in a fast way and with a flexible manner, and has the capability of ambient refractive index sensing, which makes it highly desirable for many "lab-in-fiber" applications.

Saturable absorber based on a single mode fiber - graded index fiber - single mode fiber structure with inner micro-cavity

An Er-doped mode-locked fiber laser with a saturable absorber based on single mode - graded index multimode - single mode fiber (SMF-GIMF-SMF) with inner micro-cavity is demonstrated. The modulation depth of the saturable absorber was measured to be 1.9% when the SMF-GIMF-SMF structure is bent to a certain state. Such a simple saturable absorber enables the mode-locking operation in a ring Er-doped fiber laser and ultrafast pulses with pulse energy of 0.026 nJ and pulse width of 528 fs at the fundamental repetition rate of 14.34 MHz can be generated. In addition, the harmonic mode-locking operation can also be achieved.

Fiber inline Mach-Zehnder interferometer based on femtosecond laser inscribed waveguides

A new type of Mach-Zehnder interferometer device based on in-fiber optical waveguides, fabricated by direct femtosecond laser pulse inscription in a single-mode fiber has been demonstrated and successfully employed for temperature and strain measurement. The in-fiber waveguide can couple the light out from the fiber core and guide it along the cladding region before directing it back into the fiber core. Such an inner structured interferometer device is compact and robust, can be constructed in a flexible and precisely controlled manner, and hence is expected to have many potential applications.

[The implantation of Bonebridge in bilateral congenital malformation of external and middle ear]

Objective: To evaluate the auditory efficacy of Bonebridge implantation in patients with bilateral congenital malformation of external and middle ear. Methods: Eleven cases (6 males and 5 females) had unilateral Bonebridge implantation. The age ranged from 8 to 26 and the average age was 16.9. Seven to ten days after operation, the first fitting was undergone. In acoustic sound field, the average auditory thresholds were respectively measured for unaided ears and Bonebridge implanted ears by pure tone auditory (PTA, 0.25, 0.5, 1, 2 and 4 kHz). For the group over 12-year-old, MSTM was applied to evaluate speech discrimination score (SDS). For the other cases, MLNT was used as the test material. The auditory efficacy post Bonebridge implantation would be analyzed and evaluated by comparing the differences between unaided ears and Bonebridge implanted ears. Results: The bone conduction audibility threshold after Bonebridge implantation was as well as the preoperative. The auditory threshold with Bonebridge aided was improved to 25-35 dB HL, when compared to that of the unaided ears in the sound field. The SDS in the group over 12-year-old was improved about 50%; the efficacy was slightly limited for the other two cases (both less than 12 years old). Statistical analysis showed that there were significant differences between unaided ears and Bonebridge implanted ears in the sound field and SDS(P<0.05). Conclusions: The auditory efficacy of Bonebridge is significant and noticeable in patients with bilateral congenital malformation of external and middle ear. Bonebridge provides a new and effective way for patient with congenital malformation of external and middle ear to reconstruct hearing.

Hybrid Fabry-Perot interferometer for simultaneous liquid refractive index and temperature measurement

A compact and high sensitivity sensor with a fiber-tip structure is proposed and demonstrated for simultaneously liquid refractive index (RI) and temperature sensing. The device is fabricated by inserting a tiny segment of capillary tube between single-mode fibers (SMFs) to form two cascaded Fabry-Perot interferometers (FPIs). The theoretical and experimental results demonstrate that the ambient liquid RI and temperature can be simultaneously determined by the intensity and shift of the resonant wavelength in the reflection spectrum. Our proposed device has the highest RI sensitivity of ~216.37 dB/RIU at the RI value of 1.30; a high spatial resolution owing to its compact size (with dimension <400 μm) makes it promising for high precision bio/chemical sensing applications.

[Vibrant soundbridge implantation of congenital atresia of oval window(with summary of nine cases]

Objective:To investigate the surgical effects of round window implantation of vibrant soundbridge(VSB)for patients with congenital oval window atresia.Method:Retrospectively analyze the clinical information of 9 cases of congenital oval window atresia as well as the pre-and post-operative hearing and speech results. Three of them had undergone or attempted the vestibulotomy but obtained poor results. All cases underwent round window implantation of VSB. Result:All patients obtained an improvement of 21-33 dBHL after implantation. In the speech recognition rate test, the average increase of disyllabic words was 62%, and 60% in the sentence test. During the follow-up of 51 months in average, 2 cases had a decline of auditory benefit and finally 1 case regained the improvement after reoperation. Conclusion:Round window implantation can get a fairly good result in congenital oval windows atresia cases.

Multimode fiber tip Fabry-Perot cavity for highly sensitive pressure measurement

We demonstrate an optical Fabry-Perot interferometer fiber tip sensor based on an etched end of multimode fiber filled with ultraviolet adhesive. The fiber device is miniature (with diameter of less than 60 μm), robust and low cost, in a convenient reflection mode of operation, and has a very high gas pressure sensitivity of −40.94 nm/MPa, a large temperature sensitivity of 213 pm/°C within the range from 55 to 85 °C, and a relatively low temperature cross-sensitivity of 5.2 kPa/°C. This device has a high potential in monitoring environment of high pressure.

Six-Transmembrane Epithelial Antigen of Prostate 1 (STEAP1) Has a Single b Heme and Is Capable of Reducing Metal Ion Complexes and Oxygen

STEAP1, six-transmembrane epithelial antigen of prostate member 1, is strongly expressed in several types of cancer cells, particularly in prostate cancer, and inhibition of its expression reduces the rate of tumor cell proliferation. However, the physiological function of STEAP1 remains unknown. Here for the first time, we purified a mammalian (rabbit) STEAP1 at a milligram level, permitting its high-quality biochemical and biophysical characterizations. We found that STEAP1 likely assembles as a homotrimer and forms a heterotrimer when co-expressed with STEAP2. Each STEAP1 protomer binds one heme prosthetic group that is mainly low-spin with a pair of histidine axial ligands, with small portions of high-spin and P450-type heme. In its ferrous state, STEAP1 is capable of reducing transition metal ion complexes of Fe³⁺ and Cu²⁺. Ferrous STEAP1 also reacts readily with O₂ through an outer sphere redox mechanism. Kinetics with all three substrates are biphasic with ∼80 and ∼20% for the fast and slow phases, respectively, in line with its heme heterogeneity. STEAP1 retained a low level of bound FAD during purification, and the binding equilibrium constant, K_D, was ∼30 μM. These results highlight STEAP as a novel metal reductase and superoxide synthase and establish a solid basis for further research into understanding how STEAP1 activities may affect cancer progression.

An Aromatic Cap Seals the Substrate Binding Site in an ECF-Type S Subunit for Riboflavin

ECF transporters are a family of active membrane transporters for essential micronutrients, such as vitamins and trace metals. Found exclusively in archaea and bacteria, these transporters are composed of four subunits: an integral membrane substrate-binding subunit (EcfS), a transmembrane coupling subunit (EcfT), and two ATP-binding cassette ATPases (EcfA and EcfA'). We have characterized the structural basis of substrate binding by the EcfS subunit for riboflavin from Thermotoga maritima, TmRibU. TmRibU binds riboflavin with high affinity, and the protein-substrate complex is exceptionally stable in solution. The crystal structure of riboflavin-bound TmRibU reveals an electronegative binding pocket at the extracellular surface in which the substrate is completely buried. Analysis of the intermolecular contacts indicates that nearly every available substrate hydrogen bond is satisfied. A conserved aromatic residue at the extracellular end of TM5, Tyr130, caps the binding site to generate a substrate-bound, occluded state, and non-conservative mutation of Tyr130 reduces the stability of this conformation. Using a novel fluorescence binding assay, we find that an aromatic residue at this position is essential for high-affinity substrate binding. Comparison with other S subunit structures suggests that TM5 and Loop5-6 contain a dynamic, conserved motif that plays a key role in gating substrate entry and release by S subunits of ECF transporters.