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In this paper, a novel hybrid spoof surface plasmon polaritons (SSPPs) and via-free half-mode substrate integrated waveguide (HMSIW) is proposed to constitute a compact bandpass filter (BPF). Different from the conventional HMSIW with ground holes, the grounding operation of the presented via-free HMSIW is conducted by edge grounding to bottom layer. Thus, more space can be provided for SSPPs structure. Besides, the new proposed SSPPs unit contains two shorted-end slots and one open-end slot, which not only provides abundant freedom on adjustment of desirable fundamental mode, but also the controllable of high-order modes for wide stopband. The upper cutoff frequency can be controlled by the heights of the slots of SSPPs unit and the lower cutoff frequency can be adjusted by the height of via-free HMSIW unit. Finally, a compact BPF with measured operating band of 3.01–3.81 GHz and wide stopband reaches 15.2 GHz is designed. Multiple transmission zeros generated at two sides of the passband enable the filter has high selectivity. The measured results agree well with the simulations, validating the proposed structure and design method.

Background: Oxidative stress plays a significant role in the pathogenesis of many retinal diseases. However, only a few systematic bibliometric studies have been conducted. This study aims to visualize research hotspots and developmental trends in oxidative stress in the retina from 2013 to 2023 by analyzing bibliometric data. Methods: We retrieved papers on oxidative stress in the retina published between 2013 and 2023 from the Web of Science Core Collection. The data were visually analyzed using CiteSpace and VOSviewer software. Results: The total number of 2100 publications were included in the analysis. An overall increasing trend in the number of publications is observed between 2013 and 2023. Chinese publications were the most contributive, but United States publications were the most influential. Shanghai Jiao Tong University was the most active and prolific institution. Antioxidants was the most productive journal, while Oxidative Medicine and Cellular Longevity were the journals with the most-cited articles. Kaarniranta K, from Finland, was the most productive and influential author. Examination of co-cited references revealed that researchers in the field are primarily focused on investigating the molecular mechanisms, preventive strategies, and utilization of antioxidants to address retinal oxidative damage. Diabetic retinopathy, endothelial growth factor, retinitis pigmentosa, retinal degeneration, antioxidant response, retinal ganglion cells, and genes are the research hotspots in this field. Metabolism, sodium iodate, and system are at the forefront of research in this field. Conclusion: Attention toward retinal oxidative stress has increased over the past decade. Current research focuses on the mechanisms of retinal diseases related to oxidative stress and the experimental study of antioxidants in retinal diseases, which may continue to be a trend in the future.

Abstract Conjugated microporous polymers (CMPs) are considered promising sensing materials for the detection of nitroaromatics. Unfortunately, the photoluminescence (PL) sensing application in water media is limited, owing to the poor solubility/dispersion in aqueous media. Here, two novel CMPs named poly(dimethylfluorene‐co‐tetrakis(4‐phenyl)silane)s (P4SiF) and poly(dimethylfluorene‐co‐tetrakis(3‐phenyl)silane)s (P3SiF) nanoparticles based on fluorene group and tetraphenylsilane unit are prepared using Suzuki coupling in water/toluene miniemulsion. P4SiF and P3SiF possess spherical particle morphology with sizes of 45 and 60 nm, respectively, and porous structure with pore diameters of both 1.9 nm. PL sensing experiments based on P4SiF and P3SiF nanoparticles in aqueous media show a sensitive and selective detection toward 2,4,6‐trinitrophenol (TNP). It is worth noting that the PL quenching effect toward TNP is not significantly changed after the addition of other nitro compounds, proving the excellent anti‐interference characteristic and highly selective detection of the polymers in water. Moreover, the t‐test indicates that the PL sensing method using P4SiF and P3SiF nanoparticles as sensing materials realizes the reliable detection of TNP in actual water samples at a 95% confidence level. Finally, the PL sensing mechanism is investigated, showing that the inner filter effect is the main factor in the PL quenching process of TNP in aqueous media.

A novel quadruple-mode stubs-loaded ring resonator (SLRR) is presented in this letter, which can achieve compact dual-band differential bandpass filters (BPFs) with intrinsic common-mode suppression. The differential-mode (DM) equivalent circuit and common-mode (CM) equivalent circuit of the SLRR are given and investigated by using the even-/odd-mode theory. Two DM resonances of the SLRR can be adjusted independently and are used to construct two DM passbands. Due to the magnetic-dominated coupling between two SLRRs, the intrinsic CM suppression characteristics are achieved in the differential passbands without using any additionally loaded elements. And by loading the different short-circuited coupled lines (SCCLs) at the parallel-coupled feed-line of differential BPF separately, two transmission zeros (TZs) are introduced on both sides of the DM passbands, which improves the selectivity of dual differential passbands. Furthermore, to realize the desired external Q values for two DM passbands, hybrid feeding line structure including tapped and coupled-line feeding structures is used to produce the valid excitation for the differential BPF. At the same time, the open stubs are attached to the inside of the ring resonator to reduce the filter size. Finally, two dual-band differential BPFs with central frequencies of 3.5 GHz and 4.9 GHz are designed and fabricated for fifth generation of mobile communications (5G). The measured minimum CM suppression of the two DM passbands are 31.0 dB and 34.8 dB.

In this paper, a novel dual-wideband balanced bandpass filter (BPF) based on branch-line structure is proposed. For analysis, the equivalent circuits of differential-mode (DM) and common-mode (CM) of the filter are built based on the even- and odd-mode method. With a proper synthesis design of DM bisection, dual passbands with a multi-order filtering response can be obtained. Additionally, three open-circuited stubs are centrally loaded on the CM bisection and six controllable transmission zeros are therefore generated. Thus, two stopbands are formed and then a favorable CM suppression within DM passbands is obtained. For demonstration, a third-order dual-wideband balanced BPF is designed with two passbands operating at 2.54 and 4.62 GHz. Good agreement between the simulated results and measured results is obtained, which verifies the validity of the proposed design method.

In this paper, a novel wideband differential bandpass filter (BPF) with slotline surface plasmon polaritons (SPPs) is proposed. It consists of a pair of differential microstrip-to-slotline transition, a slotline-to-SPP transition with subwavelength gradient grooves, and a slotline SPP waveguide, which supports the TEM, TE, and SPP modes, respectively. The dispersion and transmission characteristics of the proposed hybrid SPP structure are analyzed under differential-mode (DM) and common-mode (CM) operations and applied to design wideband differential filter. To validate the design concept, a filter sample has been designed, fabricated, and measured. Both simulated and measured results prove its good performance including a wide 3-dB fractional bandwidth of 147.6% centered at 4.2 GHz (f0), a wide DM upper stopband to 4.8 f0 (S21dd

A novel design method of microstrip diplexer without extra matching circuit is proposed in this paper. Because of the synthesizable circuit parameters and controllable transmission zeros (TZs) in composite resonator (CR) cell, diplexer A based on CR cell is proposed. By allocating TZs at center frequency of the opposite channel, as well as the using of impedance transformations of J inverters, high isolation and good passband selectivity are realized in diplexer A without extra matching circuit. In order to improve the stopband performance, diplexer B based on coupled CR cells is proposed. Furthermore, diplexer B using the proposed design method is implemented by directly combining two bandpass filters (BPFs), which simplifies significantly the design process of diplexers. Diplexer A operated at 1/1.2 GHz and diplexer B operated at 1/1.5 GHz are designed and fabricated. The measured isolation characteristics in diplexer A and diplexer B are all higher than 40 dB. Good agreements between simulated and measured results are achieved, which successfully verifies the proposed design method of diplexers.

Two types of short-circuited stub-embedded ring resonators (SERRs) are proposed in this paper. The resonant modes of the SERR can be designed by properly choosing the short-circuited point on the resonator. When the short-circuited point is set at the open-end of embedded-stub, type A resonator is realized and large frequency ratio of harmonic to fundamental frequency can be achieved. Simultaneously, wide stopband can be realized. When the short-circuited point is set at the loop portion of SERR, type B resonator is realized and low frequency ratio of harmonic to fundamental frequency can be achieved. These characteristics of the resonators type A and type B are explored and combined in a diplexer with common resonator part. Each channel of the diplexer are constructed by using the type A resonators for wide stopband, and then combined via a type B resonator for designated frequencies. A third-order diplexer operating at 3.45/5.8 GHz for fifth generation of mobile communications (5G) and wireless local area networks (WLAN) is designed, fabricated, and measured. Measured results agree well with the simulated ones, which confirms the proposed design methodology.

Analysis: of environmental variables and organism occurrence records offers insight that can be used to predict potential distribution areas and habitat fragmentation. For large landscapes, modeling is the most convenient and effective way to conduct habitat research. Two species distribution models, BIOMOD2 and FRAGSTATS 4.2, were given data on environmental variables and organism occurrence records as input and used to predict the potential suitable habitat and habitat fragmentation for the Yunnan snub-nosed monkey (Rhinopithecus bieti). Our results estimated the total area of potentially suitable habitat for R. bieti as 7412.82 km2, but only 4164.58 km2 was found to be inhabited by R. bieti. We found that the main land cover type in the potential suitable distribution area of R. bieti was evergreen needle-leaf forest (6153.95 km2, 83.02%). Comparison of inhabited and suitable but uninhabited habitats showed that areas actually inhabited by R. bieti had a lower patch density (PD) and higher largest patch index (LPI) than uninhabited habitats only in evergreen needle-leaf forest. The potential suitable habitats of R. bieti has increased significantly, but the actual distribution has shrunk from 1997 to 2017. Although the government has made great progress in protecting R. bieti, logging that took place before the regulations and the boundary effect of roads and rivers resulted in the local extinction of R. bieti in some potentially suitable areas. In view of this, we propose to establish a national park for Yunnan snub-nosed monkeys. We also suggest protecting the potentially suitable but currently empty habitats for later release of R. bieti. Successfully reintroducing R. bieti into areas where it formerly lived will require continual and careful habitat monitoring. Keywords: Rhinopithecus bieti, Potential distribution, Habitat fragmentation, Species distribution models

To achieve the goal of “carbon peak, carbon neutralization”, the proportion of renewable energy access will continue to increase, which will bring a severe test to the balance adjustment ability of the new power system, and the demand for flexible adjustment and real-time balance of the power system will continue to increase. However, pumped storage power stations and grid-side energy storage facilities, which are flexible peak-shaving resources, have relatively high investment and operation costs. 5G base station energy storage to participate in demand response can share the cost of energy storage system construction by power companies and communication operators to achieve a win-win situation between the communication system and the power system. Based on the analysis of the feasibility and incremental cost of 5G communication base station energy storage participating in demand response projects, combined with the interest interaction mechanism of all parties in the project, this paper proposes a business model for 5G energy storage to participate in the grid collaboration and interaction to improve the profit model of various market players, thereby promoting the penetration rate of the project.

In this paper, a new quadruple-mode stepped-impedance square ring loaded resonator (SI-SRLR) is proposed, and a high-performance dual-band differential bandpass filter (BPF) is developed. Resonant characteristics of the SI-SRLR are investigated by the even-/odd-mode method and simulation techniques. Two differential-modes (DMs) of the SI-SRLR are used to form the dual differential passbands. The admittance ratio K of the SI-SRLR is chosen appropriately to prevent the common-mode (CM) interference with DM operations. Moreover, an open-circuited stub is added to enhance the CM suppression, while a source-load coupling is introduced to produce multiple transmission zeros and improve significantly the frequency selectivity of DM passbands. Finally, a dual-band differential BPF is designed, fabricated, and measured. Good agreement between the simulated and measured results verifies well the proposed structure and design method.

We used long-term data on the variation in harem size in Yunnan snub-nosed monkeys to research the effects of harem size on reproductive success and the ratio of grooming received to given (RGRG). The results suggest that harem holders derive reproductive benefits commensurate with harem size, whereas the females’ reproductive success is unaffected by harem size. Males of larger harems groomed less and had higher RGRG than males of smaller harems. In the case of females, grooming given increased, and RGRG decreased with an increase in harem size. The males’ reproductive success seems to be a driver of harem size maximization. From the females’ perspective, dwindling social benefits appear to set the upper limit for harem enlargement. We also showed that males of monogamous units (‘single-female harems’) invested more into grooming their female, presumably to prevent unit disintegration and loss of mating privileges.

In this study, we integrate data from field investigations, spatial analysis, genetic analysis, and Generalized Linear Models (GLMs) to evaluate the effects of habitat fragmentation on the population dynamics, genetic diversity, and range shifts in the endangered Yunnan snub-nosed monkey (Rhinopithecus bieti). The results indicate that from 1994 to 2016, R. bieti population size increased from less than 2,000 to approximately 3,000 individuals. A primary factor promoting population recovery was the establishment of protected nature reserves. We also found that subpopulation growth rates were uneven, with the groups in some areas, and the formation of new groups. Both the fragmentation index, defined as the ratio of the number of forest patches to the total area of forest patches (e.g., increased fragmentation), and increasing human population size had a negative effect on population growth in R. bieti. We recommend that government conservation plans prioritize the protection of particular R. bieti populations, such as the Baimei and Jisichang populations, which have uncommon haplotypes. In addition, effective conservation strategies need to include an expansion of migration corridors to enable individuals from larger populations such as Guyoulong (Guilong) to serve as a source population to increase the genetic diversity of smaller R. bieti subpopulations. We argue that policies designed to protect endangered primates should not focus solely on total population size but also need to determine the amount of genetic diversity present across different subpopulations and use this information as a measure of the effectiveness of current conservation policies and the basis for new conservation policies.

Between September 2011 and August 2013, we studied patterns of habitat selection and habitat use in the Guizhou golden monkey (Rhinopithecus brelichi) at Fanjingshan National Nature Reserve, China. the monkeys ranged across elevations between 1432 and 2100 m. Within this altitudinal range we recorded 125 genera, 72 families, and 236 tree and vine species. From these, the Guizhou golden monkey was observe to consume food items from 104 species, 51 genera, and 31 plant families. Individual food species exploited by the monkeys varied significantly across seasons and by altitude. From October to March (Spring/Winter), the monkeys foraged across their entire 700 m elevation range. From April to September, however, individuals primarily restricted their activities to a narrow zone of between 1,700 m and 1,900 m. Our data indicate that seasonal changes in the Guizhou golden monkey dietary and ranging behavior are attributable to habitat and altitudinal specific differences in the availability of plant foods. The fact that the Guizhou golden monkey actively targets common plant foods appears to represent a low energy foraging strategy designed to minimize search time and travel. Finally, due to their ranging pattern associated with habitat specificity, all of the remaining forested habitat between 1432 and 2100 m should be protected. Keywords: Guizhou golden monkey, Altitudinal activity, Habitat selection and utilization

An ultra-wideband (UWB) bandpass filter (BPF) with a controllable notch band is presented by using hybrid microstrip/slotline structure. Firstly, a slotline resonator with symmetrically loaded stubs is fed by two microstrip lines to produce a UWB bandpass filtering response. Secondly, a microstrip triangular loop resonator is externally loaded over the slotline, and a notch band is introduced in the UWB passband. The notch band is determined by the perimeter of the loop resonator. Thirdly, two patches are added as the perturbation element to the corners of the microstrip resonator to excite a pair of degenerate modes. Bandwidth of the notch band can be tuned by properly selecting the patch size. Circuit model for the microstrip resonator loaded slotline is given and studied. Finally, the filter is designed, simulated, and measured. Measured results have agreed well with the simulated ones, demonstrating that a UWB filter with a controllable notch band has been realized.

A wide-band microstrip bandpass filter (BPF) based on the improved composite right/left-handed transmission line (CRLH-TL) structure is presented in this paper. Compared to the traditional CRLH-TL with via hole, the improved one is an all-planar structure, which owns the advantage of fabrication and loss. The equivalent lossless LC circuit model of the proposed structure is established. EM software Sonnet is adopted to design the wide-band filter with bandwidth of 1.4 GHz (from 1.9 GHz to 3.3 GHz). The circuit occupies only 20.6 × 12.8 mm2. Finally, the fabrication and measurement are implemented. A good agreement between simulation and measured results verifies the validity of the design methodology.

Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of animal consumption by the snub-nosed monkey (Rhinopithecus bieti) in a wild, habituated group between 2004 and 2009 in Yunnan, China. At present, only males in an all-male unit within the study group were involved in active hunting. Such a male-biased activity may be related to the group structure and spatial spread of R. bieti. Two females were observed eating freshly killed birds. The findings confirmed that R. bieti engaged in scavenging and, when hunting, employed a cranio-cervical bite to kill their prey. Meat eating is likely a nutrient maximization feeding strategy in R. bieti, especially in males. A begging behavior occurred after successful prey capture. Although begging was observed, no sharing of the meat was seen. The present findings illuminate the dietary diversity of R. bieti and their ability to expand their dietary spectrum [Current Zoology 56 (2 ): 227–231, 2010].

Sexual selection typically produces ornaments in response to mate choice, and armaments in response to male–male competition. Unusually among mammals, many primates exhibit colour signals that may be related to one or both processes. Here, we document for the first time correlates of facial coloration in one of the more brightly coloured primates, the black-and-white snub-nosed monkey (Rhinopithecus bieti). Snub-nosed monkeys have a one-male unit (OMU) based social organization, but these units aggregate semi-permanently into larger bands. This form of mating system causes many males to become associated with bachelor groups. We quantified redness of the prominent lower lip in 15 males (eight bachelors, seven OMU holders) in a group at Xiangguqing, China. Using mixed models, our results show that lip redness increases with age. More interestingly, there is a significant effect of the interaction of group-holding status and mating season on redness; that is, lip colour of OMU males undergoes reddening in the mating season, whereas the lips of subadult and juvenile bachelor males become paler at that time of year. These results indicate that lip coloration is a badge of (group-holding) status during the mating season, with non-adults undergoing facial differentiation, perhaps to avoid the costs of reproductive competition. Future research should investigate whether lip coloration is a product of male–male competition, and/or female mate choice.

A miniaturized bandpass filter (BPF) using defected ground structure (DGS) resonator with the characteristic of harmonic rejection is developed in this paper. The second and third harmonics of the proposed BPF are rejected by the characteristic of stepped-impedance DGS resonator. Moreover, open stubs are established so that two adjustable transmission zeros can independently be created to extend the stopband and improve the rejection level. Finally, a second-order BPF, centered at 1.62 GHz with a stopband extended up to 5.6 GHz and a rejection level better than 20 dB, is designed and implemented for GPS application. A good agreement between simulation and measurement verifies the validity of this design methodology.

High-altitude dwelling primates have to optimize navigating a space that contains both a vertical and horizontal component. Black-and-white or Yunnan snub-nosed monkeys (Rhinopithecus bieti) are extreme by primate standards in inhabiting relatively cold subalpine temperate forests at very high altitudes where large seasonal variation in climate and food availability is expected to profoundly modulate their ranging strategies so as to ensure a positive energy balance. A “semi-nomadic” group of R. bieti was followed for 20 months in the montane Samage Forest, Baimaxueshan Nature Reserve, Yunnan, PRC, which consisted of evergreen conifers, oaks, and deciduous broadleaf trees. The aim of this study was to disentangle the effects of climate and phenology on patterns of altitudinal range use. Altitude used by the group ranged from a maximum of 3550 m in July 2007 to a minimum of 3060 m in April 2006. The proportional use of lichen, the monkeys’ staple fallback food, in the diet explained more variation in monthly use of altitudes than climatic factors and availability of flush and fruit. The abundance of lichens at high altitudes, the lack of alternative foods in winter, and the need to satisfy the monkey's basal energetic requirements explain the effect of lichenivory on use of altitudes.

BACKGROUND: Allomaternal nursing, common in several species of social mammals, also has been reported in nonhuman primates. However, the function of this behavior in enhancing infant survivorship remains poorly understood. METHODOLOGY AND PRINCIPAL FINDINGS: The study was conducted on a free-ranging group of the Yunnan snub-nosed monkey (Rhinopithecus bieti) in the Baimaxueshan Natural Reserve. Direct observation and ad libitum sampling were used to record allocare behavior during a 20 month field study. R. bieti exhibits a multilevel social organization in which a large single troop, consisting of over 100 individuals, is divided into many one-male units (OMUs: 6∼41). These OMUs coordinate their daily activities, and feed, forage, travel, and rest together. Here we report on one case of infant temporary adoption in which an adult female from one OMU engaged in allomaternal nursing and cared for an infant from a different OMU of the same troop. This event began when the mother and her five-month-old infant were found to became separated accidentally. The victim infant was observed staying in another OMU. Over the next several days we observed a lactating female in the new OMU to care for and nurse both her infant and the immigrant infant, who also was tolerated by and cared for by the harem male. CONCLUSIONS AND SIGNIFICANCE: Our findings suggest that lactating primate females are primed to care for young infants and, that the misdirected parental care hypothesis may offer the strongest explanation for allomaternal nursing in R. bieti.

BACKGROUND: Infanticide by adult male occurs in many mammalian species under natural conditions, and it is often assumed to be a goal-directed action and explained predominately by sexual selection. Motivation of this behavior in mammals is limitedly involved. METHODOLOGY AND PRINCIPAL FINDINGS: We used long-term reproductive records and direct observation in captivity and in the field of two snub-nosed langur species on the basis of individual identification to investigate how infanticide happened and to be avoided in nonhuman primates. Our observations suggested that infanticide by invading males might be more accidental than goal-directed. The invading male seemed to monopolize all the females including lactating mothers during takeovers. Multiparous mothers who accepted the invading male shortly after takeovers avoided infanticide in most cases. Our results conjectured primiparous mothers would decrease infanticidal possibility if they sexually accepted the invading male during or immediately after takeovers. In the studied langur species, voluntary abortion or mating with the invading male was evidently adopted by females to limit or avoid infanticide by takeover males. CONCLUSIONS AND SIGNIFICANCE: The objective of the invading male was to monopolize all adult females after his takeover. It appeared that the mother's resistance to accepting the new male as a mating partner was the primary incentive for infanticide. Motivation analysis might be helpful to further understand why infanticide occurs in primate species.

A low profile and high selectivity filtering slot antenna based on circular substrate integrated waveguide (SIW) cavity is presented. The proposed antenna is originated from a circular SIW cavity operating at its TM010 mode. A cruciform slot is integrated on the top surface of the cavity, and the cavity is then split into four quarter-mode cavity resonators. In this aspect, the four similar quarter-TM010 modes will be generated by the compact structure. By amalgamating four similar modes into a single-band, the bandwidth of antenna is widened. Based on the structure, a filtering slot antenna with central frequency of 8 GHz and bandwidth of 5.6% is designed and fabricated. Measured results agree well with the simulated ones. In addition, two radiation nulls are produced at the edges of the passband, and the selectivity in the transition band is enhanced greatly. [ABSTRACT FROM AUTHOR]

In this paper, an antipodal Vivaldi antenna (AVA) with a lower cutoff frequency is proposed based on spoof surface plasmon polaritons (SSPPs) and corrugated edges. Firstly, the gradient slots are etched on the outer edges of the two radiation arms of the conventional antipodal Vivaldi antenna. As a result, the low cutoff frequency is decreased slightly due to the increased surface current path of the antenna. More importantly, the SSPPs structure with identical units is etched on the inner side of two radiation arms, leading to a significant reduction in the low cutoff frequency due to the larger propagation constant of the SSPPs structure compared to the radiation arms of the conventional antipodal Vivaldi antenna. Additionally, the structure of the SSPPs on the stripline ensures effective momentum and mode matching between the quasi-TEM mode and SSPPs mode. Furthermore, to improve the gain at the high-frequency band, the structure of the SSPPs introduced on the inner side of the two radiation arms is further optimized by varying the depths of the grooves. Experimental results demonstrate that the designed antipodal Vivaldi antenna exhibits excellent radiation performance, with a low cutoff frequency of 2.8 GHz and a maximum gain of 9.3 dBi. [ABSTRACT FROM AUTHOR]