Reference-frame-independent quantum key distribution with advantage distillation.

Advantage distillation (AD) provides a means of separating highly correlated raw key bits from weakly correlated information in quantum key distribution (QKD). In this Letter, we apply the AD method to improve the performance of reference-frame-independent QKD (RFI-QKD). Simulation results show that, compared with RFI-QKD without AD, RFI-QKD with AD can tolerate higher system errors and obtain better performance on the secret key rate and transmission distance. Furthermore, we extend the AD method to RFI measurement-device-independent QKD (RFI-MDI-QKD) and demonstrate that the AD method can improve the performance of RFI-MDI-QKD more significantly.

Improved reference-frame-independent quantum key distribution: erratum.

We present an erratum to our Letter [Opt. Lett.47, 4219 (2022)10.1364/OL.470558]. This erratum corrects the error results of Figs. 2 and 4 due to the error in the simulation code. The corrections have no influence on the conclusions of the original Letter.

[Measurements of Bacterial Community and Biodiversity from Activated Sludge for a Wastewater Treatment Containing Starch].

This study analyzes the microbial community and diversity composition of activated sludge in anoxic/oxic (A/O) treatment systems at different operation stages using Illumina MiSeq high-throughput sequencing to investigate the microbial community structure and diversity in activated sludge for starch wastewater treatment. The experimental results showed that the microbial community structure of activated sludge for starch production wastewater treatment in A/O systems was quite stable under the same wastewater condition, and that the dominant bacteria of the activated sludge were Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, and Actinobacteria. The most important dominant bacterial group was Proteobacteria (45.66%-66.30%), of which γ-subclass bacteria were the main member and occupied 36.38%-66.65%. The proportion of Sphingobacteria, the main member of the Bacteroidetes, decreased when the sludge settling performance was better, but the proportion of Anaerolineae, the main member of Chloroflexi, increased significantly when the sludge sedimentation performance was better. These changes may have been closely related to the behavior of sludge settleability. There were a large number of functional bacteria in the activated sludge, which played an important role in the degradation of pollutants and in nitrogen and/or phosphorus removal.

Experimental quantum key distribution with uncharacterized sources and projective measurements.

In theory, quantum key distribution (QKD) can offer information-theoretic secure communication based on the laws of quantum mechanics. However, the vast majority of practical QKD implementations assume the perfect state preparation to ensure security, which is a demanding requirement with current technology. Here, by incorporating the mismatched-basis data, we report an experimental decoy-state QKD demonstration with uncharacterized encoding sources, which only requires that the encoding states are two-dimensional. Furthermore, the measurement operation of the receiver is loosened to be projective measurements. With a rigorous statistical fluctuation analysis, we can distribute secret keys when the transmission distances of the standard fiber link are 101 and 202 km. Our experimental demonstration represents a significant step toward realizing long-distance quantum communication, even with uncharacterized sources and projective measurements.

Crystal structures and properties of two hydrated conglomerate forms of the heart-rate-lowering agent ivabradine hydrochloride.

Ivabradine hydrochloride (IVA-HCl) (systematic name: {[3,4-dimethoxybicyclo[4.2.0]octa-1(6),2,4-trien-7-yl]methyl}[3-(7,8-dimethoxy-2-oxo-2,3,4,5-tetrahydro-1H-3-benzazepin-3-yl)propyl]methylazanium), is a novel medication used for the symptomatic management of stable angina pectoris. In many recent patents, it has been claimed to exist in a very large number of polymorphic, hydrated and solvated phases, although no detailed analysis of the structural features of these forms has been published to date. Here, we have successfully crystallized the tetrahydrate form of IVA-HCl (form ß), C27H37N2O5+·Cl-·4H2O, and elucidated its structure for the first time. Simultaneously, a new crystal form of IVA-HCl, i.e. the hemihydrate (form II), C27H37N2O5+·Cl-·0.5H2O, was discovered. Its crystal structure was also accurately determined and compared to that of the tetrahydrate form. While the tetrahydrate form of IVA-HCl crystallized in the orthorhombic space group P212121, the new form (hemihydrate) was solved in the monoclinic space group P21. Detailed conformational and packing comparisons between the two forms have allowed us to understand the role of water in the crystal assembly of this hydrochloride salt. The stabilities of the two forms were compared theoretically by calculating the binding energy of the water in the crystal lattice using differential scanning calorimetry (DSC). The stability experiments show that the tetrahydrate is stable under high-humidity conditions, while the hemihydrate is stable under high-temperature conditions.

A new polymorph of the gastrokinetic drug cisapride monohydrate.

Cisapride monohydrate (systematic name: 4-amino-5-chloro-N-{(3RS,4SR)-1-[3-(4-fluorophenoxy)propyl]-3-methoxypiperidin-4-yl}-2-methoxybenzamide monohydrate), C23H29ClFN3O4·H2O, is a nondopamine-blocking gastrokinetic drug. A new polymorph of cisapride monohydrate has been reported nearly three decades after the report of its first known crystal structure [Collin et al. (1989). J. Mol. Struct. 214, 159-175]. The second polymorph is also monoclinic, but with different unit-cell parameters. A comparison of both polymorphic forms shows that the difference is thus not in the molecular conformation but in the arrangements of molecules in the crystal packing. The crystal morphology of two forms was predicted with the BFDH model in Materials Studio and inferred that the powder of the new polymorph has better flowability than the original polymorph. The results of DSC (differential scanning calorimetry) analysis and slurry experiments show that both polymorphs are stable at room temperature.

Improved statistical fluctuation analysis for measurement-device-independent quantum key distribution with four-intensity decoy-state method.

Recently Zhang et al [ Phys. Rev. A95, 012333 (2017)] developed a new approach to estimate the failure probability for the decoy-state BB84 QKD system when taking finite-size key effect into account, which offers security comparable to Chernoff bound, while results in an improved key rate and transmission distance. Based on Zhang et al's work, now we extend this approach to the case of the measurement-device-independent quantum key distribution (MDI-QKD), and for the first time implement it onto the four-intensity decoy-state MDI-QKD system. Moreover, through utilizing joint constraints and collective error-estimation techniques, we can obviously increase the performance of practical MDI-QKD systems compared with either three- or four-intensity decoy-state MDI-QKD using Chernoff bound analysis, and achieve much higher level security compared with those applying Gaussian approximation analysis.

Role of N-acyl homoserine lactone (AHL)-based quorum sensing (QS) in aerobic sludge granulation.

N-acyl homoserine lactone (AHL)-based quorum sensing (QS) has been recognized to play an important role in the formation of biofilm. However, aerobic granular sludge is considered as a special biofilm, and its biological implication and role of AHL-based QS still remain unclear. This study investigated the role of AHL-based QS in aerobic granulation. Results showed that AHLs were necessary to the typical aerobic granulation, and AHL-associated coordination of bacteria in sludge aggregation was sludge density dependent only when it reached a threshold of 1.010 g/mL; AHL-based QS was activated to regulate aerobic granulation. Furthermore, a quorum quenching method was firstly adopted to investigate the role of AHLs in aerobic granules. Results showed inhibition of AHL by acylase that reduced the AHL content in aerobic granules and further weakened its attachment potential, which proved that AHLs play an important role in the formation of aerobic granules. Additionally, the assay of quorum quenching not only proved that AHL-based QS could regulate EPS production but also provided additional evidence for the role of AHLs in aerobic granulation by regulating EPS content and its component proportion.

[Cultivation of aerobic granules in a large pilot SBR with domestic sewage].

The cultivation of aerobic granules in a large pilot-scale SBR was investigated using domestic wastewater. After operation of 210 days, the granules with a diameter of 330 microm were successfully formed by seeding anaerobic digested sludge. Results showed that, during the first three months of operation under low organic load of influent, removal efficiencies of pollutants increased steadily including COD, NH(4+)-N, total nitrogen (TN) and total phosphorous (TP). Meanwhile, microorganisms related to nitrogen and phosphorous were enriched. The organic load was enhanced since cycle time was shortened to 6 h, and the operational performance of the reactor still remained stable. Moreover, the average particle size of the sludge started to increase, along with excellent settling ability and high bioactivity. After the formation of aerobic granules, Sludge volume index (SVI) was maintained at 30 mL x g(-1) and the mixed liquor suspended solid (MLSS) concentration in the SBR reached 8.8 g x L(-1). MLVSS/MLSS ratio of the sludge increased to 82% with a high oxygen uptake rate (OUR) of 5.32 mg x (min x L)(-1). Bacillus was dominant on the outer layer of granules, while cocci were mainly located inside. The average COD and TP removal efficiencies kept at 90% and NH(4+) -N was almost completely depleted, NO(3-) -N and NO(2-) -N were not accumulated in the effluent. The aerobic granules were also capable of achieving simultaneous nitrification and denitrification (SND) in a single SBR cycle, which resulted in a high TN removal efficiency of 80%.

[Cultivation of aerobic granules by a method of alternative feed loading].

The formation process and morphological and physicochemical properties of aerobic granules were examined in a SBR system by a method of alternative feed loading. The results showed that the aerobic granules could be quickly and effectively cultivated using the alternative feeding COD 400, 800, 1200 mg/L [feed loading 0.96, 1.92 and 3.84 kg/(m3 x d)] when other conditions were fixed. The developed granules of the reactor were maintained in MLSS 20-22 g/L and SVI 14-16 mL/g. The average size of completely granular particles was 613.6 microm in diameter. The cocci occupied mainly in outer layer of granules, and both cocci and rods existed in inner layer of particles. The granules reached 95% COD removal and 97% NH4+ -N-removal simultaneously. The analysis of FISH showed AOB was distributed in outer surface of aerobic granules, and NOB existed in outer and inner layer small amounts of aerobic granules.

[Characteristics of operational performance and membrane fouling in a sidestream membrane sequencing batch reactor with aerobic granule].

The characteristics of operational performance and membrane fouling were investigated using synthetic wastewater as feed in a sidestream membrane sequencing batch reactor (MSBR) system. The experimental results showed that the average removal efficiencies of COD, TN, TP and NH4+ -N were 90%, 60%-80%, 80% and 95% respectively under the influent COD of 200 mg x L(-1) to 1200 mg x L(-1) during more than 150 days' operation. It was possible to achieve a complete granulation of sludge. In 70th day, sludge particles around 350 microm were detected more than 90%. From then, sludge grew up continuously and finally reached to 394 microm in diameter. With the formation of granular sludge in MSBR, the cleaning time of membrane system was prolonged to 65 days, which was larger than three times compared with flocculent sludge MSBR. It was also much better than conventional MBR. These results clearly demonstrated that the formation of granular sludge was good for improving the resistance to organic loading shock and retaining the membrane fouling of the system, and maintaining the stable operation for a long time.

[Characteristics of membrane fouling and its control in membrane sequencing batch reactor process].

Characteristics of membrane fouling and its control were investigated using synthetic wastewater as feed in an anaerobic/aerobic membrane sequencing batch reactor (MSBR) for 300 days operational period. The experimental results showed that the sludge was in flocculent form, and the range of SVI was 64.6-110.6 mL x g(-1) during the initial 75 days operation. Membrane fouling occurred in a quick exponential growth, and the average growth rate of TMP was 0.309 kPa x d(-1). Membrane resistance was in the range of 0.393 x 10(11) - 1.298 x 10(11) m(-1) x d(-1) and specific membrane flux decreased from 4.4 L x (m2 x h x kPa) (-1) to 0.52 L x (m2 x h x kPa)(-1). The critical membrane flux was 20 L x (m2 x h)(-1) at 75th day. In 75-120 d operation, MSBR condition was regulated, and aerobic granular sludge in reactor appeared. SVI decreased steadily, and finally maintained approximately 40 mL x g(-1) from 170th day on. The sludge particle grew much gradually, and size distribution was mainly in diameter 500-1000 microm at 220th day. Membrane fouling developed very slowly. The average accumulating rate of TMP was only 0.062 kPa x d(-1) membrane resistance varied from 0.291 x 10(11) m(-1) x d(-1) to 0.404 x 10(11) m(-1) x d(-1), specific membrane flux decreased from 4.4 L x (m2 x h x kPa)(-1) to 1.4 L x (m2 x h x kPa) (-1) and critical membrane flux was 40 L x (m2 x h)(-1) at 220th day. These data clearly demonstrated that the formation of aerobic granular sludge was beneficial to cease the growth rate of membrane fouling. Specific membrane flux was the biggest at aeration strength of 100 m3 x (m2 x h)(-1) while membrane fouling rate was the lowest at aeration strength of 69 m3 x (m2 x h)(-1).

[Filamentous overgrowth in aerobic granules].

Filamentous overgrowth has been observed after aerobic granulation in shaking sequencing batch reactors (SSBR). The factors affecting the filamentous overgrowth in aerobic granules and its possible control methods were investigated. It was found that both the influent and sludge inoculation largely influenced the filamentous overgrowth in aerobic granules. With the same activated sludge inoculation, the filamentous overgrowth in R3 treating fresh wastewater was much more severe than that in R1 treating saline wastewater. The filamentous overgrowth in R2 was the least among the three reactors, which was inoculated anaerobic granules and treated saline wastewater. When the filamentous overgrowth happened at the outer aerobic granules, Delta referring the degree of filamentous overgrowth achieved DeltaR1 = 1.4, DeltaR2 = 1.2 and DeltaR3 = 2.0, respectively. Filamentous identification showed that the filamentous microorganisms in R1 mainly composed of Eikelboom 0092 and Nocardia spp., Fungi spp. and Nocardia spp. in R2, S. natans and H. hydrossis in R3. The identified filamentous microorganisms likely occurred in conditions with long SRT, low dissolved oxygen and biodegradable substrates. However, due to the fact that filamentous overgrowth in aerobic granules initiated in the inner part of the granules and acted as frameworks with rod-shape or coccoid bacteria entrapping into in the granulation period, various strategies effectively in dealing with conventional bulking problems including shorting SRT, changing organic loading rate and enhancing aeration et al, could not effectively inhibit the filamentous growth in aerobic granules. The filamentous overgrowth was ultimately controlled through changing the substrate from synthetic glucose-rich wastewater to non-biodegradable wastewater.

Calcium spatial distribution in aerobic granules and its effects on granule structure, strength and bioactivity.

Calcium-rich aerobic granules were cultivated after 3-month operation. The chemical form and spatial distribution of calcium in the granules and their physicochemical characteristics were explored. Examination with a scanning electron microscope combined energy dispersive X-ray detector (SEM-EDX) shows that Ca was mainly accumulated in the core of the granules. CaCO(3) was found to be the main calcium precipitate in the granules. The fluorescent in situ hybridization (FISH) analysis shows that the cells were crowded in the outer layer and gathered in clusters. Compared with the granules without Ca accumulation, the Ca-rich granules had more rigid structure and a higher strength. However, their specific oxygen uptake rate (SOUR) reduced after the Ca accumulation inside them. Comparison between the SOUR values of the granules with and without Ca accumulation suggests that Ca accumulated in the aerobic granules might have a negative effect on their bioactivity.

[Experimental investigation of high saline wastewater treatment using aerobic granules].

Complete aerobic granulation could be achieved in shaking sequencing batch reactors (SSBR) with saline wastewater respectively inoculated conventional activated sludge and anaerobic granules. Pretty good specific TOC removal rates could be achieved without inoculating the halo-bacteria at the start-up time. When the salinity was less than 10 g/L NaCl with the synthetic glucose-rich wastewater as substitute, the TOC removal efficiency was in the range of 70.3%-97.6%. After the salinity was 35 g/L NaCl and the influent was completely changed to Vc wastewater as substrate, similar TOC removal efficiency about 70% could be achieved compared with the performance of fresh Vc wastewater treatment under the same condition. The granules in saline wastewater had a diameter of 0.5-3 mm, and saline aerobic granules had much higher settling velocity, higher oxygen utilization rate (OUR), lower sludge production and better structural integrity than those of the granules from fresh wastewater. Saline aerobic granules showed perfect protecting-ability against the saline shock and could quickly recover from long term sharp saline change. Due to the different sludge inoculation, the aerobic granules from aerobic flocs had superior TOC removal performance and inferior saline shock protecting-ability compared with the aerobic granules from anaerobic granules.

[Diagnosis and treatment of pulmonary hypertension caused by sleep hypoventilation: analysis of 4 cases in a family].

OBJECTIVE: To summarize the experience in diagnosis and treatment of pulmonary hypertension caused by sleep hypoventilation. METHODS: The clinical data of 4 patients in a family with pulmonary hypertension caused by sleep hypoventilation, full brothers and sisters, 2 (Cases 1 and 2) being treated presently and 2 (Cases 3 and 4) being deceased and traced by family medical history, were retrospectively analyzed. RESULTS: Three of the 4 cases (cases 1, 3, and 4) were misdiagnosed as with cor pulmonale combined with pulmonary hypertension, and one case (case 2) was misdiagnosed as with primary pulmonary hypertension. Polysomnography (PSG) revealed alveolar hypoventilation-induced long period of oxygen desaturation at sleep in Cases 1 and 2, thus confirming the diagnosis. Pulmonary function test showed that the percentage of maximum inspiratory pressure (PImax) in predicted value (51.5% and 20.9%) and the maximum expiratory pressure (PEmax) in predicted value (51.3% and 29.6%) decreased, the percentage of mouth occlusion pressure (P0.1) in predicted value (141% and 133%) compensatively increased, and the respiratory muscle strength decreased in Cases 1 and 2, which suggested that there was neuromuscular disorder in these patients. Treated by noninvasive ventilation the symptoms of these 2 patients were improved and they were discharge at last. Subsequently, they were treated by long-term night noninvasive ventilation at home, and returned to normal work and life. During the follow-up for 22 and 12 months respectively after discharge, PSG showed that the alveolar hypoventilation-induced long period oxygen desaturation at sleep had been greatly improved, and echocardiogram showed that the pulmonary pressure was greatly decreased. CONCLUSION: For the patients with unexplained pulmonary hypertension, PSG monitoring and pulmonary function tests such as PImax, PEmax, and P0.1 help determine the etiology, and long-term night noninvasive ventilation at home can improve the outcome of sleep hypoventilation-induced pulmonary hypertension.

[Investigation of nitrogen removal performance with membrane sequencing batch reactor process].

Nitrogen removal performance was investigated using synthetic wastewater as feed without sludge discharge in an anaerobic/aerobic membrane sequencing batch reactor (MSBR) during 300 days operation. The results showed that MLSS in reactor was retained up to about 18 g x L(-1), sludge size larger than 100 microm was 96%, and aerobic granular sludge was developed. The bacterial community observation of AOB and NOB by FISH-CLSM for sludge revealed that they were existed in larger numbers. When influent NH(4+) -N concentration was about 50 mg x L(-1), effluent NH(4+) -N concentration was lower than to 1 mg x L(-1), and nitrification could complete in 180-210 min. There was a good correlation between nitrification reaction and aeration strength. When aeration strength was 100 m3 x (m2 x h)(-1), NH(4+) -N degradation rate 24.25 mg x (L x h)(-1), and nitrification reaction in MSBR was stable. The main factor determining nitrogen removal of the system was denitrification rate, which was optimal at aeration 69 m3 x (m2 x h)(-1), when the nitrification rate of NO(3-) -N 10.98 mg x (L x h)(-1), effluent NO(3-) -N 4.4 mg x L(-1), and NO(3-) -N in the beginning of anaerobic phase 3.5 mg x L(-1). The denitrification performance was not benefited by excessive aeration or deficient aeration. Bigger volumetric exchange ratio was helpful for nitrogen removal and the system treatment capacity. The C/N ratio 2 was suitable to good denitrification rate, while there was a NO(2-) -N accumulation if C/N ratio was larger than 2.

[Investigation of aerobic granular sludge cultivation by feed loading as a control strategy].

The key cultivation strategy for aerobic granular sludge cultivation was investigated using feed loading control as a main operational parameter in an aerobic/anaerobic SBR system. The results showed that the feed loading by influent COD 0-900 mg x L(-1) could effectively control the growth of sludge. The settling characteristic of inoculated sludge was important for aerobic granules formation, and its SVI 20-50 mg x L(-1) was favourable to granulation development process. Pure aeration without substrate feeding can greatly improve the settleability of sludge, and stimulate the granulation process. The activated sludge with good settleability could be converted to completely aerobic granular sludge through reducing operational loading in a certain condition. The granulation process occurred in COD feeding 400-500 mg x L(-1), and sludge concentration 8-10 g x L(-1). The developed granules were approximately 1.0 mm in diameter, SVI 25-35 mg x L(-1), settling velocity 60 m x h(-1). The authors proposed that granulation formation process was attributed to a unique operational mode in SBR system, i.e. the famine-feast alternation of substrate in reactor. The control strategy of organic loading by reducing substrate could enhance the variation of famine-feast in substrate, and made the driving force for granulation development.

[Experimental investigation of aerobic granule cultivation in high strength Vc wastewater].

Aerobic granular sludge was cultivated in sequencing batch reactors (SBRs) fed with high strength and refractory real Vc wastewater. In the reactor treated transformation residues, it was achieved a completely aerobic granulation, and the sludge was 0.2-1 mm in diameter, average settling velocity 31.2 m x h(-1). In another reactor treated refinery or extracted residue, partially granular formation was reached, and the sludge was 0.5-2.5 mm in diameter, average settling velocity 26.3 m x h(-1). The formation of good aerobic granules contributed a good operational property. When influent COD was 1,000-1,500 mg x L(-1), COD removal efficiency was maintained approximately 80%. It could be improved better by adding biodegradable organic matters in feed. Through microscopic observation of sludge from two different reactors, the protozoa and biodiversity of microorganisms in reactors were determined not only by the operational parameters, but also by the influent composition. The granulation process in the experiment was proceeded through three stages, i. e. sludge activation phase, acclimatization phase and aerobic granulation phase. In operation control, the settling-time was used as the key factor for the formation of aerobic granules, which could decant the flocculent sludge and regulate the organic loading, and eventually promote the granulation process.

[Lung transplantation in the treatment of ventilator dependent end-stage lung diseases: report of three cases].

OBJECTIVE: To investigate the perioperative management, recipient selection of end-stage lung diseases dependent on ventilator, and the strategy of ventilator weaning. METHODS: Fifteen patients underwent lung transplantation in our hospital from 2002 to 2005. Of them, three were dependent on ventilator for 89, 120 and 107 days respectively because of end-stage pulmonary emphysema before operation. Single-lung transplantation was performed in one patient and sequential bilateral single-lung transplantations were performed in two patients without extracorporeal circulation. RESULTS: The three patients were weaned from ventilator in the sixth, eleventh and twenty second day respectively after operation. They were discharged from hospital 71 d, 41 d, and 67 d respectively after operation. They had been followed up for 22, 4, and 2 months respectively before this analysis. Their quality of life improved significantly. CONCLUSION: Lung transplantation is effective for the treatment of ventilator dependent end-stage lung diseases.