Offspring nursing extends mother's longevity in a long-term maternal cared spider.

Females typically outlive males in animals, especially in species that provide long-term maternal care. However, life history theory predicts that investments in reproduction, such as lactation and offspring nursing, often shorten caretakers' longevity. Aiming to interpret this paradox, we selected the lactating jumping spider Toxeus magnus to investigate the effects of reproductive activities on longevity for two sexes. We found that: (1) although "milk" provisioning reduces female's longevity, mothers who cared for offspring (provisioned "milk" and nursing) lived the longest compared to virgins and those did not provide care; (2) copulation increased female's longevity but had no effects on males; and (3) the two sexes have comparable developmental duration, but the female adult's longevity was 2.1 times that of male's. This study suggests that the time requirement for offspring dispersal might act as a key selective force favoring females' adulthood extension, which ultimately generates the longer-lived females in maternal cared species.

Ants may buffer the Janzen-Connell effect in a tropical forest in Southwest China.

Mutualistic symbioses between ants and plants are widespread in nature. Ants can deter unwanted pests and provide protection for plants in return for food or housing rewards. Using a long-term demographic dataset in a tropical seasonal rain forest in Southwest China, we found that associations with ants positively influenced seedling survival and adult growth, and also, species with extrafloral nectaries experienced weaker conspecific negative density dependence compared with species without extrafloral nectaries. Furthermore, we found strong evidence suggesting that species in our forest experienced conspecific density dependence, which we interpreted as heavy pest pressure that may drive the development of anti-pest symbioses such as the plant-ant relationship. Our findings suggest that ants and conspecific neighbors play important but inverse roles on plant survival and growth and that ants can buffer tree neighborhood interactions in this tropical forest.

Petal-shaped femoral lobes facilitate gliding in orchid mantises.

To glide in forest canopies, arboreal vertebrates evolved various skin-derived aerodynamic structures, such as patagial membranes or webbing, but no comparable structure has been reported from wingless arboreal arthropods.1,2,3 Orchid mantises (Hymenopus coronatus) have been traditionally considered a textbook example of flower mimicry for ∼200 years due to their highly expanded, petal-shaped femoral lobes. However, the empirical evidence substantiating the petal-mimicry function of the femoral lobes has not been entirely conclusive.4,5,6 Observational and experimental evidence suggests that these lobes do not contribute to flower mimicry for luring pollinators6,7 and likely serve other functions.7,8 After observing their aerial escape initiated with active jumping, we hypothesized that orchid mantises can glide and that their femoral lobes are used for gliding. Through behavioral investigations and morphological analyses, we show that orchid mantis nymphs are excellent gliders, exhibiting the shallowest gliding trajectories observed in terrestrial invertebrates.9,10,11,12,13 The lobe extensions on their femoral segments are cambered airfoils, which increase the mantis projected area by ∼36% and play a vital role in the aerodynamic underpinning of the observed gliding. Despite a 165-fold increase in body mass throughout ontogeny, older female mantis nymphs maintained a persistent gliding capability. We further showed a notable 40%-56% reduction in wing loading attributed to the positive size allometry of these lobes, indicating a clear promotion of gliding throughout ontogeny. This is the first documentation of gliding-adapted "leg wings" in a wingless arthropod. The evolution of such structures is potentially common among arboreal arthropods and demands a systematic re-examination.

Stimuli-responsive mechanically interlocked molecules constructed from cucurbit[n]uril homologues and derivatives.

Cucurbit[n]uril supramolecular chemistry has developed rapidly since 2001 when different cucurbit[n]uril homologues (Q[n]) were successfully separated in pure form. The combination of Q[n] cavity size and various types of external stimuli has given birth to numerous types of Q[n]-based mechanically interlocked molecules (MIMs), including (pseudo)rotaxanes, catenanes, dendrimers and poly(pseudo)rotaxanes. In this review article, the important advances in the field of Q[n]-based MIMs over the past two decades are highlighted. This review also describes examples of heterowheel (pseudo)rotaxanes and poly(pseudo)rotaxanes involving Q[n]s, and reflects on the opportunities and challenges of constructing Q[n]-based stimuli-responsive MIMs.

You are what you eat: nutrient and water relations between mistletoes and hosts.

Mistletoes play important roles in biogeochemical cycles. Although many studies have compared nutrient concentrations between mistletoes and their hosts, no general patterns have been found and the nutrient uptake mechanisms in mistletoes have not been fully resolved. To address the water and nutrient relations in mistletoes compared with their hosts, we measured 11 nutrient elements, two isotope ratios and two leaf morphological traits for 11 mistletoe and 104 host species from four sites across a large environmental gradient in southwest China. Mistletoes had significantly higher phosphorus, potassium, and boron concentrations, nitrogen isotope ratio, and lower carbon isotope ratio (δ13 C) indicative of lower water-use efficiency than hosts, but other elements were similar to those in hosts. Sites explained most of the variation in the multidimensional trait space. With increasing host nitrogen concentration, both mistletoe δ13 C and the difference between mistletoe and host δ13 C increased, providing evidence to support the 'nitrogen parasitism hypothesis'. Host nutrient concentrations were the best predictors for that of the mistletoe nutrient elements in most cases. Our results highlight the important roles of environmental conditions and host nutrient status in determining mistletoe nutrient pools, which together explain their trophic interactions with hosts in subtropical and tropical ecosystems.

Supramolecular Host-Guest Hydrogel Based on γ-Cyclodextrin and Carboxybenzyl Viologen Showing Reversible Photochromism and Photomodulable Fluorescence.

Much effort has been devoted to the development of supramolecular hydrogels due to their broad applications and conveniently controllable properties. Here, we demonstrate a novel supramolecular host-guest hydrogel, which is constructed by the host γ-CD complexed with the guest 1-(4-carboxybenzyl)-4,4'-bipyridinium chloride (1+·Cl-) through the π···π interaction, hydrogen bonding, and host-guest interactions. The supramolecular hydrogel [1+@γ-CD]n exhibits reversible electron transfer photochromic behavior and photomodulable fluorescence. The excellent photochromic and fluorescence properties support the practical utility of the supramolecular hydrogel as a visual display and anti-counterfeiting material.

An inclusion complex of cucurbit[7]uril with benzimidazolyl benzyl viologen exhibits fluorescence and photochromic properties.

In order to investigate the photochromic mechanism of photochromic materials based on supramolecular host-guest systems, we designed and synthesized a unique viologen derivative (benzimidazolyl benzyl viologen, guest 1·Cl3), which does not contain oxygen atoms. The binding interaction of guest 13+ with host cucurbit[7]uril (Q[7]) was investigated by various techniques. The obtained supramolecular host-guest complex 13+@Q[7] exhibits interesting fluorescence emission and reversible photochromism. The ESR and XPS experimental data suggest that the photochromic process of the complex 13+@Q[7] comes from the electron transfer from the carbonyl O atoms of the host Q[7] to the bipyridinium N atoms of the guest 13+.

Study on the Pyrolysis and Adsorption Behavior of Activated Carbon Derived from Waste Polyester Textiles with Different Metal Salts.

In this study, the effects of the catalysis of heavy metals on the pyrolysis of waste polyester textiles (WPTs) and the adsorption behaviors of the pyrolysis products of WPTs for Cr(VI) were explored. TG-DTG analysis indicated that the metal ions catalyzed the pyrolysis process by reducing the temperature of the decomposition of WPTs. The surface morphology and pore structure of the carbons were analyzed using SEM and BET. The results demonstrated that Zn-AC possessed the largest specific surface area of 847.87 m2/g. The abundant acidic functional groups on the surface of the activated carbons were proved to be involved in the Cr(VI) adsorption process via FTIR analysis. Cr(VI) adsorption experiments indicated that the adsorption process was more favorable at low pH conditions, and the maximum adsorption capacities of Zn-AC, Fe-AC, and Cu-AC for Cr(VI) were 199.07, 136.25, and 84.47 mg/g, respectively. The FTIR and XPS analyses of the carbons after Cr(VI) adsorption, combined with the adsorption kinetics and isotherm simulations, demonstrated that the adsorption mechanism includes pore filling, an electrostatic effect, a reduction reaction, and complexation. This study showed that metal salts catalyze the pyrolysis processes of WPTs, and the activated carbons derived from waste polyester textiles are promising adsorbents for Cr(VI) removal.

Mirror image stimulation could reverse social-isolation-induced aggressiveness in the high-level subsocial lactating spider.

Conspecific aggressiveness often increases after social isolation for species that are not entirely solitary, and this increased aggression could also be reversed after resocialization. However, literature on this aggression plasticity refers to either permanently social or low-level subsocial species in invertebrates. Examinations of conspecific aggressiveness reversibility in high-level subsocial invertebrates, in which offspring cohabitate with parents for a certain period of time after sexual maturation, would enhance the understanding of the role of conspecific-aggression plasticity in social evolution. Here, using the lactating spider Toxeus magnus, which exhibits extremely high-level subsociality, we assessed three questions. (1) Is its conspecific aggression affected by social living and/or kinship? The results indicated that conspecific aggression increased after social isolation, while kinship did not affect aggressiveness. (2) Could the social-isolation-induced higher aggression be reversed after resocialization? The results showed that the increased aggression of the spiders could be reversed 3 days after resocialization. (3) What is the proximate mechanism that caused the aggression reversibility by resocialization? A simulated resocialization experiment in which single spider was provided with mirrors demonstrated that the visual cues of conspecifics alone could reverse the aggression after 6 days. These results indicate that the high-level subsocial invertebrate showed aggressiveness reversibility without chemical cues. This is more similar to permanently social species rather than to low-level subsocial species, and visual cues could be vital to induce aggression change. These results suggest that conspecific-aggression reversibility might play a key role in social evolution and may functionally enhance species' adaptiveness under variable conditions.

A light-responsive molecular switch based on cucurbit[7]uril and 1,1'-bis(benzyl)-4-[2-(4-pyridyl)-vinyl]-pyridinium dibromide displaying white light emission.

By using 1H NMR, ESI-MS and UV spectra, a novel light-responsive molecular switch constructed using 1,1'-bis(benzyl)-4-[2-(4-pyridyl)-vinyl]-pyridinium (12+) and cucurbit[7]uril (Q[7]) is demonstrated. The E- to Z-isomerization of the double bond in 12+ results in the transition of the switching states from the 1 : 2 complex E-12+@Q[7]2 to the stable 1 : 1 complex Z-12+@Q[7]. In particular, both the 1 : 2 complex and the 1 : 1 complex can emit cold white fluorescence under UV light.

How fern and fern allies respond to heterogeneous habitat - a case in Yuanjiang dry-hot valley.

The Yuanjiang dry-hot valley features hot and dry climate, low vegetation and soil degradation. It had lush vegetation in the past, but has become degraded in recent decades. Understanding the interrelationship between species and the habitat is necessary to explain this change. In this study, a link between fern and fern allies - a group that is hypersensitive to environmental factors and their circumstances is constructed. Intensive transects and plots were designed to be proxies for extant fern and fern allies, and their habitats. Fifty years of meteorological records of precipitation and temperature along altitude and river running direction (latitudinal) were employed. Alpha and beta diversity are used to access diversity. Species_estimated, Singletons, Uniques, ACE, ICE, and Chao2, which associate to abundance and rarity, are subscribed to the correlation between fern and fern allies, and their ecosystem. Eight species, Selaginella pseudopaleifera, Aleuritopteris squamosa, Adiantum malesianum, Pteris vittata, Davallia trichomanoides, Sinephropteris delavayi, Selaginella jugorum, and Lygodium japonicum are used as indicators of a typical xeric and sun-drying habitat. The results indicate (1) accompanied by dramatically shrinking habitats, fern and fern allies are in very low diversity and abundance, whereas the rarity is relatively high; (2) for fern and fern allies, environmental factors are positive when altitude goes up; and (3) eight indicator species are latitudinally correlated with fern and fern allies along the river running direction.

Two sexes respond equally to food restriction in a sexually dimorphic but not body mass dimorphic jumping spider.

Natural selection favors animals that evolve developmental and behavioral responses that buffer the negative effects of food restrictions. These buffering responses vary both between species and within species. Many studies have shown sex-specific responses to environmental changes, usually in species with sexual size dimorphism (SSD), less found in species with weak or no SSD, which suggests that sizes of different sexes are experiencing different selections. However, previous studies usually investigated development and behavior separately, and the balanced situation where males and females of sexually dimorphic species respond in the same way to food restriction remains little known. Here, we investigated this in Phintelloides versicolor (Salticidae) that presents sexual dimorphism in color and shape but weak SSD. We examined whether food restriction induced the same responses in males and females in development duration, adult body size and weight, daily time allocated to foraging, and hunting. We found food restriction induced similar responses in both sexes: both exhibited longer development duration, smaller adult body size and weight, higher probability of staying outside nests and noticing prey immediately, and higher hunting success. However, there were sexual differences regardless of food condition: females showed faster development, smaller adult body size, higher probability of staying outside of nests, and higher hunting success. These indicated the differential selection on male and female sizes of P. versicolor could be under a balanced situation, where males and females show equal developmental and behavioral plasticity to environmental constraints.

[Preparation and Evaluation of Intranasal in situ Gel of Bupleuri Radix Volatile Oil and Baicalin].

OBJECTIVE: To prepare and evaluate a new formulation of thermosensitive and ion-sensitive in situ gel for nasal administration, using the volatile oil of Bupleuri radix and baicalin, the effective component extracted from Scutellariae radix . METHODS: Formulation of in situ nasal gel of Bupleuri radix volatile oil and baicalin was prepared by using poloxamer 407 and deacetylated gellan gum as the gel base, 10% pharmasolve and 2% polysorbate 80 as the solubilizer, and 0.8% triethanolamine as the pH regulator. The physical appearance, phase transition temperature, and baicalin release performance of the prepared gel were examined. The pharmacodynamic evaluation was done with the rat fever model developed with dry yeast and the mouse auricle swelling inflammation model. RESULTS: The phase transition temperature of the gel was optimized to be 36 ℃. The release of baicalin from the gel showed obvious features of sustained release, which accorded well the zero-order kinetics equation. The results of experiments with the rat dry yeast fever model and the mouse xylene auricle swelling inflammation model showed that the gel had significant antipyretic and anti-inflammatory effects that were significantly better than those of the groups treated with the blank gel base and the Bupleuri radix and Scutellariae radix granule. Results from the cilia toxicity test showed that the gel did not have obvious toxic effect on toad palate mucosal cilia. CONCLUSION: The in situ nasal gel of Bupleuri radix volatile oil and baicalin prepared in the study had a rapid onset time, high efficiency, and prolonged release of active ingredients, thus showing promises for further applicational development.

Detecting Pesticide Dodine by Displacement of Fluorescent Acridine from Cucurbit[10]uril Macrocycle.

According to a simple guest-replacement fluorescence turn-on mechanism, we constructed a fluorescent probe system based on cucurbit[10]uril (Q[10]) and protonated acridine (AD) to detect the pesticide dodine (DD). Formation of a homoternary inclusion complex AD2@Q[10] in both aqueous solution and solid state was studied by means of 1H NMR spectroscopy and X-ray crystallography. Although AD can emit strong fluorescence in aqueous solution, the homoternary inclusion complex AD2@Q[10] does not exhibit any fluorescence. Upon the addition of the pesticide DD into the aqueous solution of AD2@Q[10], the AD molecules in the Q[10] cavity are displaced by the pesticide DD, and strong fluorescence recovers. The fluorescent probe system based on Q[10] and AD provided a wide determination of DD from 0 to 4.0 × 10-5 mol·L-1 with a low limit of detection of 1.827 × 10-6 mol·L-1. The guest-replacement fluorescence turn-on mechanism is also confirmed by 1H NMR spectroscopy. Further, the fluorescent probe can directly detect DD residues in real agricultural products, and obvious fluorescence signal was observed under UV irradiation.

Selective Recovery and Detection of Gold with Cucurbit[n]urils (n = 5-7).

Environmentally benign methods for gold recovery and detection are highly desirable for a sustainable future. Herein, we demonstrate a selective recovery and detection strategy of gold with cucurbit[n]urils (Q[n = 5-7]) by means of outer-surface interactions. Tetrachloroaurate anion ([AuCl4]-) is able to be rapidly precipitated with Q[n] in forms of supramolecular adducts. X-ray crystallography of four Q[n = 5-7]·[AuCl4]- complexes reveal that strong outer-surface interactions between Q[n = 5-7] and [AuCl4]- are the major driving force for the formation of Q[n = 5-7]·[AuCl4]- complexes. Impressively, each Q[6] macrocycle is surrounded by 12 [AuCl4]- anions. Each of these 12 [AuCl4]- anions is connected to four adjacent [AuCl4]- anions, leading to the formation of a three-dimensional supramolecular framework with tubular channels. In addition, we found an interesting inclusion complex [Au(OH2)4]3+⊂Q[7] in the Q[7]·[AuCl4]- complex, which is the first example of hydrated metal cation encapsulated inside the cavity of Q[n]. Spectroscopic data suggest that Q[n = 5-7] possess a high affinity and selectivity for [AuCl4]- even in the presence of other transition-metal ions. Q[n] modified electrodes are found to be an effective material for the detection of trace gold in dilute solutions.

Symmetrical-Tetramethyl-Cucurbit[6]uril-Driven Movement of Cucurbit[7]uril Gives Rise to Heterowheel [4]Pseudorotaxanes.

Two novel heterowheel [4]pseudorotaxanes consisting of cucurbit[7]uril (Q[7]) and symmetrical-tetramethyl-cucurbit[6]uril (TMeQ[6]) were constructed via the multirecognition mechanism, in which Q[7] can rotate freely around the horizontal axis, while TMeQ[6] cannot. In the construction process, due to strong repulsive forces between carbonyl portals of two neighboring wheels, the dethreading and movement of the wheels along the axle was observed. The dissociation of the [4]pseudorotaxanes was also discussed.

Selective recognition and determination of phenylalanine by a fluorescent probe based on cucurbit[8]uril and palmatine.

This paper demonstrated a simple and validated fluorescence enhancing method to selectively recognize and discriminate the amino acid phenylalanine (Phe). 1H NMR spectroscopy reveal that the palmatine (PAL) can be encapsulated into the cucurbit [8]uril (Q [8]) in aqueous solution to form stable 1:2 host-guest inclusion complex PAL2@Q [8], which exhibits moderate intensity fluorescence property. Interestingly, the addition of the Phe into the inclusion complex PAL2@Q [8] leads to dramatically enhancing of the fluorescence intensity. In contrast, the addition of any other natural amino acids into the inclusion complex PAL2@Q [8] gives no fluorescence variation. Furthermore, it is easy to detect the concentration of Phe in target aqueous solution according to the linear relationship between fluorescence intensity and concentration of the Phe.

Contrast-enhanced computed tomography findings of a huge perianal epidermoid cyst: A case report.

BACKGROUND: Epidermoid cysts can be found at any location in the human body. However, perianal epidermoid cysts are extremely rare and only a few cases have been reported. As far as we know, there is no special literature on the value of contrast-enhanced computed tomography (CT) for the diagnosis of perianal epidermoid cysts. CASE SUMMARY: A 60-year-old male patient presented to the department of general surgery of PLA Strategic Support Force Characteristic Medical Center with the chief complaint of a mass in the perianal region gradually expanding for more than 30 years and perianal discomfort upon sitting for a preceding period of 2 mo. Physical examination revealed a painless mass in the left perianal region. Contrast-enhanced CT was used for preoperative diagnosis. The patient was treated by total mass excision under epidural anesthesia. Postoperative pathological examination revealed the presence of a perianal epidermoid cyst. The patient showed a satisfactory recovery during the 6-month follow-up period. CONCLUSION: Contrast-enhanced CT may be a beneficial, useful, and convenient approach for assistance for preoperative diagnosis and surgical decision-making for patients with perianal epidermoid cysts.

Outer surface interactions to drive cucurbit[8]uril-based supramolecular frameworks: possible application in gold recovery.

Q[8]-based honeycomb-like frameworks can be obtained in [AuCl4]--free aqueous HNO3 solution and aqueous HCl and HNO3 solutions that contain [AuCl4]-. The outer surface interaction of Q[8] with planar inorganic anions [AuCl4]- and NO3- is the main driving force. These frameworks exhibit a high selectivity for imprisoning [AuCl4]- that could establish a process for gold recovery.