In China, shi hu (stems of Dendrobium chrysotoxum Lindl, D. fimbriatum Hook. D. huoshanense Z.Z. Tang & S.J. Cheng, or D. nobile Lindl) and tie pi shi hu (stems of D. officinale Kimura et Migo) are ...famous traditional medicines and are listed in the Chinese Pharmacopoeia. However, the leaves of these Dendrobium plants are largely discarded.
To better utilize Dendrobium leaves, we summarize their traditional uses, chemical constituents, pharmacological activities, and toxicological effects.
“Orchidaceae”, “Dendrobium”, “leaf”, “traditional use”, and “ethnobotany” were used as search terms to screen the literature. Cited references were collected between 1960 and 2020 from the Web of Science, China National Knowledge Internet (CNKI), SciFinder, and Google Scholar, primarily in English and Chinese.
Traditional uses of leaves from 16 Dendrobium species were identified in the literature. The major uses of Dendrobium leaves include treatments for dermatologic disorders, metabolic syndromes, nervous system disorders, and musculoskeletal system disorders. More than 50 chemical compounds have been identified in the leaves of 10 Dendrobium species, which primarily include flavonoids, bibenzyls, coumarins, N-containing compounds, and polysaccharides. Antihyperlipidemia, antihypertensive, antihyperuricemia, anti-inflammatory, antimicrobial, antioxidant, cytotoxic and antitumor, hepatoprotective, immunomodulatory, lipase-inhibitory, and/or tyrosinase-inhibitory activities have been reported for the leaves of six Dendrobium species. D. officinale leaves have been shown to exhibit no reproductive toxicity against male rats, while D. speciosum Sm. leaves have been observed to exhibit slight genotoxicity in an in vitro study. Among Dendrobium species, D. officinale leaves are the most widely studied.
D. officinale leaves represent a good example of the utilization of leaf resources of the Dendrobium genus. In the future, more extensive research for the development of Dendrobium leaves is needed.
A planting base and collected leaves of Dendrobium officinale in Yunnan, China. Display omitted
Calixarenes (CAs), representing the third generation of supramolecular hosts and one of the most widely studied macrocyclic scaffolds, offer (almost) unlimited structure and application possibilities ...due to their ease of modification, which allows one to establish a large molecular library as a material basis for diverse biomedical applications. Moreover, CAs and their derivatives engage in various noncovalent interactions for the facile recognition of guests including bioactive molecules and are also important building blocks for the fabrication of supramolecular architectures. In view of their molecular recognition and self‐assembly properties, CAs are extensively applied in biosensing, bioimaging, and drug/gene delivery. Additionally, some CA derivatives exhibit biological activities and can therefore be used as new therapeutic agents. Herein, we summarize the diverse biomedical applications of CAs including in vitro diagnosis (biosensing), in vivo diagnosis (bioimaging), and therapy.
Calixarenes (CAs) represent the third generation of supramolecular hosts and one of the most widely studied macrocyclic scaffolds. They offer almost unlimited structural possibilities due to their ease of modification, providing a tremendous molecular library as a material basis for diverse biomedical applications.
High-throughput sequencing of ribosomal RNA gene (rDNA) amplicons has opened up the door to large-scale comparative studies of microbial community structures. The short reads currently produced by ...massively parallel sequencing technologies make the choice of sequencing region crucial for accurate phylogenetic assignments. While for 16S rDNA, relevant regions have been well described, no truly systematic design of 18S rDNA primers aimed at resolving eukaryotic diversity has yet been reported. Here we used 31,862 18S rDNA sequences to design a set of broad-taxonomic range degenerate PCR primers. We simulated the phylogenetic information that each candidate primer pair would retrieve using paired- or single-end reads of various lengths, representing different sequencing technologies. Primer pairs targeting the V4 region performed best, allowing discrimination with paired-end reads as short as 150 bp (with 75% accuracy at genus level). The conditions for PCR amplification were optimised for one of these primer pairs and this was used to amplify 18S rDNA sequences from isolates as well as from a range of environmental samples which were then Illumina sequenced and analysed, revealing good concordance between expected and observed results. In summary, the reported primer sets will allow minimally biased assessment of eukaryotic diversity in different microbial ecosystems.
Enhanced drug delivery can improve the therapeutic efficacy of drugs and help overcome side effects. However, many reported drug‐delivery systems are too complex and irreproducible for practical use. ...In this work, the design of a hypoxia‐responsive molecular container based on calixarene, called CAC4A, which presents a significant advance in practical, hypoxia‐targeted drug‐delivery, is reported. CAC4A enables a wide variety of clinical drugs to be quantitatively loaded to improve their solubility and stability, as well as enable the administration of reduced doses. Furthermore, as a result of its azo functional groups, which are sensitive to reduction within a hypoxic environment, it is possible to achieve tumor‐targeted drug‐release with reduced side effects. CAC4A fulfils all essential requirements for a drug‐delivery system in addition to multiple advantages, including facile preparation, well‐defined molecular weight, and structure, and universal applicability. Such features collectively enable supramolecular prodrugs to be formulated simply and reproducibly, with potential for bench‐to‐bedside translation. Moreover, CAC4A is amenable to other therapy modalities and can be facilely decorated with functional groups and hybridized with nanomaterials, providing ample possibilities for its role in future drug‐delivery systems.
Carboxylated azocalix4arene is designed as a hypoxia‐responsive molecular container, which affords strong binding toward a series of chemotherapeutic drugs, and improves the drugs’ solubility and stability, demonstrating its universality as a supramolecular drug carrier. Taking one supramolecular prodrug as an example, the efficacy of this hypoxia‐targeted therapy is validated in vitro and in vivo.
Physicians, particularly trainees and those in surgical subspecialties, are at risk for burnout. Mistreatment (i.e., discrimination, verbal or physical abuse, and sexual harassment) may contribute to ...burnout and suicidal thoughts.
A cross-sectional national survey of general surgery residents administered with the 2018 American Board of Surgery In-Training Examination assessed mistreatment, burnout (evaluated with the use of the modified Maslach Burnout Inventory), and suicidal thoughts during the past year. We used multivariable logistic-regression models to assess the association of mistreatment with burnout and suicidal thoughts. The survey asked residents to report their gender.
Among 7409 residents (99.3% of the eligible residents) from all 262 surgical residency programs, 31.9% reported discrimination based on their self-identified gender, 16.6% reported racial discrimination, 30.3% reported verbal or physical abuse (or both), and 10.3% reported sexual harassment. Rates of all mistreatment measures were higher among women; 65.1% of the women reported gender discrimination and 19.9% reported sexual harassment. Patients and patients' families were the most frequent sources of gender discrimination (as reported by 43.6% of residents) and racial discrimination (47.4%), whereas attending surgeons were the most frequent sources of sexual harassment (27.2%) and abuse (51.9%). Proportion of residents reporting mistreatment varied considerably among residency programs (e.g., ranging from 0 to 66.7% for verbal abuse). Weekly burnout symptoms were reported by 38.5% of residents, and 4.5% reported having had suicidal thoughts during the past year. Residents who reported exposure to discrimination, abuse, or harassment at least a few times per month were more likely than residents with no reported mistreatment exposures to have symptoms of burnout (odds ratio, 2.94; 95% confidence interval CI, 2.58 to 3.36) and suicidal thoughts (odds ratio, 3.07; 95% CI, 2.25 to 4.19). Although models that were not adjusted for mistreatment showed that women were more likely than men to report burnout symptoms (42.4% vs. 35.9%; odds ratio, 1.33; 95% CI, 1.20 to 1.48), the difference was no longer evident after the models were adjusted for mistreatment (odds ratio, 0.90; 95% CI, 0.80 to 1.00).
Mistreatment occurs frequently among general surgery residents, especially women, and is associated with burnout and suicidal thoughts.
It is well known that the channel capacity of traditional MIMO systems is positively correlated with the number of antennas, so MIMO systems usually use more antennas to meet higher system capacity ...requirements, which is increasingly conflicting with the miniaturization requirements of portable devices. To overcome the above problems, a new OvTDM-MIMO system is proposed, which can effectively improve the capacity of the system. This system introduces the overlapped time division multiplexing (OvTDM) technology into the MIMO system, which can further improve the channel capacity of the MIMO system by using a smaller number of antennas. This paper introduces the transceiver model of the OvTDM-MIMO system in detail and derives the channel capacity of the system based on mutual information theory. Compared with a conventional MIMO system, the OvTDM-MIMO system has the ability to improve channel capacity. Then, this paper proposes an OvTDM-MIMO symbol detection scheme based on an improved low-complexity Orthogonal Approximate Message Passing (OAMP) algorithm to solve the symbol detection problem caused by symbol correlation. The main design idea of this scheme is to use symbol correlation as the detection constraint and realizes joint symbol detection by combining adjacent symbols, avoiding the problem of excessive matrix size caused by Kronecker product operation. The simulation results show that the proposed detection algorithm can achieve similar performance to traditional MIMO system detection algorithms with low computational complexity.
Dopamine (DA), as one of the central neurotransmitters, plays an important role in many physiological and pathological processes. Detection of DA is critical to diagnose and monitor some neurological ...diseases. In this work, a novel on-off ratiometric electrochemical sensor with molecularly imprinted polymers (MIPs) as target molecule recognizer has been developed for selective and accurate detection of DA. Nanoporous gold (NPG) was electrodeposited on bare gold electrode, which not only benefited the output signal amplification, but also provided enlarged surface for immobilization of polythionine (pThi) and MIPs. Oxidation of DA and pThi served as response signal and internal reference signal, respectively. The oxidation peak currents of DA at +0.12 V increased with increasing the concentration of DA, while the peak currents of pThi at −0.2 V decreased simultaneously. Due to the specificity from MIPs and the built-in correction from pThi, the fabricated sensor showed excellent performance in view of selectivity and reproducibility. It's worth to mention that even if the surface area and morphology of working electrode underwent huge variation deliberately, the assay deviation among these ratiometric sensors was largely reduced around 10 times. The proposed sensor demonstrated a broad dynamic range of 0.3–100 μM, as well as a low detection limit of 0.1 μM (S/N = 3). Moreover, superior anti-interfering ability toward DA detection was obtained despite the presence of interferents at high concentration in artificial cerebrospinal fluid (aCSF). Therefore, this work is expected to provide an alternative pathway for constructing ratiometric electrochemical sensor and offer reliable determination of small molecules with high selectivity and stability.
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•A ratiometric electrochemical dopamine sensor was designed to improve the reproducibility and robustness.•Molecularly imprinted polymer was served as dopamine molecule recognizer with enhanced specificity.•Measurement error was controlled effectively even though sensors with diverse areas and morphologies were adopted.•The sensors showed excellent DA sensing performance in artificial cerebrospinal fluid (aCSF).
Perfluorinated alkyl substances, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are toxic materials that are known to globally contaminate water, air, and soil resources. ...Strategies for the simultaneous detection and removal of these compounds are desired to address this emerging health and environmental issue. Herein, we develop a type of guanidinocalix5arene that can selectively and strongly bind to PFOS and PFOA, which we use to demonstrate the sensitive and quantitative detection of these compounds in contaminated water through a fluorescent indicator displacement assay. Moreover, by co-assembling iron oxide nanoparticle with the amphiphilic guanidinocalix5arene, we are able to use simple magnetic absorption and filtration to efficiently remove PFOS and PFOA from contaminated water. This supramolecular approach that uses both molecular recognition and self-assembly of macrocyclic amphiphiles is promising for the detection and remediation of water pollution.
We introduce novel image regularization penalties to overcome the practical problems associated with the classical total variation (TV) scheme. Motivated by novel reinterpretations of the classical ...TV regularizer, we derive two families of functionals involving higher degree partial image derivatives; we term these families as isotropic and anisotropic higher degree TV (HDTV) penalties, respectively. The isotropic penalty is the mixed norm of the directional image derivatives, while the anisotropic penalty is the separable norm of directional derivatives. These functionals inherit the desirable properties of standard TV schemes such as invariance to rotations and translations, preservation of discontinuities, and convexity. The use of mixed norms in isotropic penalties encourages the joint sparsity of the directional derivatives at each pixel, thus encouraging isotropic smoothing. In contrast, the fully separable norm in the anisotropic penalty ensures the preservation of discontinuities, while continuing to smooth along the line like features; this scheme thus enhances the linenlike image characteristics analogous to standard TV. We also introduce efficient majorize-minimize algorithms to solve the resulting optimization problems. The numerical comparison of the proposed scheme with classical TV penalty, current second-degree methods, and wavelet algorithms clearly demonstrate the performance improvement. Specifically, the proposed algorithms minimize the staircase and ringing artifacts that are common with TV and wavelet schemes, while better preserving the singularities. We also observe that anisotropic HDTV penalty provides consistently improved reconstructions compared with the isotropic HDTV penalty.
Dendrobium
Sw. is one of the largest genera in the orchidaceous family and includes 900–2000 species. Among them, more than 80
Dendrobium
species have been reported in China. However, there are only ...six
Dendrobium
species, namely,
D. bigibbum
var.
superbum
(syn.
D. phalaenopsis
),
D. chrysanthum
,
D. fimbriatum
,
D. loddigesii
,
D. nobile
, and
D. officinale
(syn.
D. candidum
), listed in the New Inventory of Existing Cosmetic Ingredients in China Launched. Artificial planting of
Dendrobium
species has been a great success in China. To better utilize
Dendrobium
resources for medicinal and cosmetic purposes, we summarize their traditional uses and pharmacologically active compounds for treating dermatological disorders in this review. “Orchidaceae”, “
Dendrobium
”, “traditional use”, “ethnobotany”, “dermatological disorder”, and “skin disease” were used as search terms to screen the literature. Cited references were collected between 1970 and 2020 from the Web of Science, China National Knowledge Internet (CNKI), SciFinder, Google Scholar, and Chinese books. From the search, it was found that there are 22
Dendrobium
species with traditional uses in dermatological disorders, and 131 compounds from
Dendrobium
plants have been reported to possess anti-inflammatory, antimicrobial, antioxidant, antiaging, anti-psoriasis, and tyrosinase-inhibitory activities, implying that
Dendrobium
plants are important resources for the discovery of active compounds and the development of new drugs and cosmetics.
D. crepidatum
,
D. denneanum
,
D. loddigesii
,
D. nobile
, and
D. officinale
have been extensively studied. More research on other
Dendrobium
species is needed. The major active compounds found in
Dendrobium
species are phenanthrenes, alkaloids, flavonoids, phenylpropanoids, and lignans. Several compounds, such as loddigesiinol A, (
S
)-5-methoxy-2,4,7,9-tetrahydroxy-9,10-dihydrophenanthrene, (
S
)-4-methoxy-2,5,7,9-tetrahydroxy-9,10-dihydrophenanthrene, 2,5-dihydroxy-4-methoxy-phenanthrene 2-
O
-
β
-
d
-glucopyranoside, (9
R
)-1,2,5,9-tetrahydroxy-9,10-dihydrophenanthrene 5-
O
-
β
-
d
-glucopyranoside, (+)-homocrepidine A, and vicenin 2, have significant anti-inflammatory activities and inhibit nitric oxide (NO) production with IC
50
values less than 5 μM, and these compounds are worthy of further study.
Graphic Abstract
PDF
![Guanidinocalix[5]arene for ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2041-1723/small "Guanidinocalix[5]arene for sensitive fluorescence detection and magnetic removal of perfluorinated pollutants")
