Prenatal DEHP exposure induces lifelong testicular toxicity by continuously interfering with steroidogenic gene expression.

Background: Epidemiologic studies suggested the association between prenatal di-(2-ethylhexyl) phthalate (DEHP) exposure and disorders of sex development (DSD), adult male disorders, and reproductive aging. Inhibiting testosterone synthesis by interfering with steroidogenic gene expression induces testicular toxicity, however, whether prenatal DEHP exposure induces testicular toxicity through this mechanism remains uncertain. Methods: C57BL/6JGpt male mice underwent different doses (0, 100, 500, 1,000 mg/kg) of prenatal DEHP exposure during gestational day 10 to delivery day, the testicular toxicity (genital development, testosterone, semen quality, and morphology of testis tissue) in the neonatal, post-puberal and middle-aged stages was observed, and the steroidogenic gene (Lhcgr, Star, Cyp11a1, Cyp17a1, Hsd17b3, and Hsd3b2) expression was analyzed by quantitative polymerase chain reaction (qPCR) and Western blot (WB). The interference of steroidogenic gene expression in TM3 cells after mono-(2-ethylhexyl) phthalate (MEHP) exposure was also explored for verification. Results: Prenatal DEHP exposure induced immediate testicular injury in the neonatal stage [reduced anogenital distance (AGD) and intratesticular testosterone], DSD in the post-puberal stage (poor genital development), and reproductive aging in the middle-aged stage (obesity, reduced testosterone and semen quality, and atrophic seminiferous tubules), especially in the high dose. Prenatal DEHP exposure continuously interfered with steroidogenic gene expression (Hsd3b2, Hsd17b3) in RNA and protein levels. MEHP inhibited testosterone synthesis of TM3 cells by interfering with steroidogenic gene expression (Hsd3b2, Hsd17b3) in RNA and protein levels. Conclusions: Prenatal DEHP exposure induces lifelong testicular toxicity by continuously interfering with steroidogenic gene expression, thus indicating the association between prenatal exposure and DSD, adult male disorders, and reproductive aging.

Stem Leydig cells support macrophage immunological homeostasis through mitochondrial transfer in mice.

As testicular mesenchymal stromal cells, stem Leydig cells (SLCs) show great promise in the treatment of male hypogonadism. The therapeutic functions of mesenchymal stromal cells are largely determined by their reciprocal regulation by immune responses. However, the immunoregulatory properties of SLCs remain unclear. Here, we observe that SLCs transplantation restore male fertility and testosterone production in an ischemia‒reperfusion injury mouse model. SLCs prevent inflammatory cascades through mitochondrial transfer to macrophages. Reactive oxygen species (ROS) released from activated macrophages inducing mitochondrial transfer from SLCs to macrophages in a transient receptor potential cation channel subfamily member 7 (TRPM7)-mediated manner. Notably, knockdown of TRPM7 in transplanted SLCs compromised therapeutic outcomes in both testicular ischemia‒reperfusion and testicular aging mouse models. These findings reveal a new mechanism of SLCs transplantation that may contribute to preserve testis function in male patients with hypogonadism related to immune disorders.

Skeleton-CutMix: Mixing Up Skeleton With Probabilistic Bone Exchange for Supervised Domain Adaptation.

We present Skeleton-CutMix, a simple and effective skeleton augmentation framework for supervised domain adaptation and show its advantage in skeleton-based action recognition tasks. Existing approaches usually perform domain adaptation for action recognition with elaborate loss functions that aim to achieve domain alignment. However, they fail to capture the intrinsic characteristics of skeleton representation. Benefiting from the well-defined correspondence between bones of a pair of skeletons, we instead mitigate domain shift by fabricating skeleton data in a mixed domain, which mixes up bones from the source domain and the target domain. The fabricated skeletons in the mixed domain can be used to augment training data and train a more general and robust model for action recognition. Specifically, we hallucinate new skeletons by using pairs of skeletons from the source and target domains; a new skeleton is generated by exchanging some bones from the skeleton in the source domain with corresponding bones from the skeleton in the target domain, which resembles a cut-and-mix operation. When exchanging bones from different domains, we introduce a class-specific bone sampling strategy so that bones that are more important for an action class are exchanged with higher probability when generating augmentation samples for that class. We show experimentally that the simple bone exchange strategy for augmentation is efficient and effective and that distinctive motion features are preserved while mixing both action and style across domains. We validate our method in cross-dataset and cross-age settings on NTU-60 and ETRI-Activity3D datasets with an average gain of over 3% in terms of action recognition accuracy, and demonstrate its superior performance over previous domain adaptation approaches as well as other skeleton augmentation strategies.

Ningmitai capsules have anti-inflammatory and pain-relieving effects in the chronic prostatitis/chronic pelvic pain syndrome mouse model through systemic immunity.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) seriously affects the physical and mental health of approximately 90% of males. Due to its complex and unclear etiology, the treatment methods that are currently available for chronic prostatitis/chronic pelvic pain syndrome are controversial, and their efficacy is unsatisfactory. At present, most researchers believe that this kind of prostatitis is caused by autoimmune inflammation. Chinese herbs, which are the essence of traditional Chinese medicine (TCM), are emerging treatment options for inflammation and immune diseases. In this experiment, we investigated the effect of Ningmitai capsules (a kind of traditional Chinese medicine widely used to treat lower urinary tract inflammation and pain in males) on chronic prostatitis/chronic pelvic pain syndrome in a non-obese diabetes-experimental autoimmune prostatitis (NOD-EAP) mouse model. First, by using bioinformatics analysis of data from the Encyclopedia of Traditional Chinese Medicine (ETCM) database, we found that quercetin, which is one of the main components of Ningmitai capsules, could reduce the secretion of CCL2 by inhibiting the MAPK pathway. In animal experiments, it was found that after Ningmitai treatment, the inflammation in mouse prostates was alleviated, the expression of CCL2, which is related to pain, and MAPK pathway components were downregulated, and the activation of the inflammatory NF-κB and STAT3 pathways was reduced. Pelvic pain and inflammation were relieved in mice with EAP. Due to the presence of the blood-prostate barrier, the drug may not completely reach the prostate directly and take effect locally. However, we found that after Ningmitai treatment, the proportions of proinflammatory CD11b+Ly6Chigh immune cells in the spleen, bloodstream (systemic immunity), and prostate (local immunity) were reduced. The infiltration of CD11b+ immune cells into the spleen and prostate was decreased. These findings suggested that Ningmitai can treat chronic prostatitis/chronic pelvic pain syndrome by affecting systemic and local immunities through the CCL2-MAPK pathway.

Research hotspots and frontiers in agricultural multispectral technology: Bibliometrics and scientometrics analysis of the Web of Science.

Multispectral technology has a wide range of applications in agriculture. By obtaining spectral information during crop production, key information such as growth, pests and diseases, fertilizer and pesticide application can be determined quickly, accurately and efficiently. The scientific analysis based on Web of Science aims to understand the research hotspots and areas of interest in the field of agricultural multispectral technology. The publications related to agricultural multispectral research in agriculture between 2002 and 2021 were selected as the research objects. The softwares of CiteSpace, VOSviewer, and Microsoft Excel were used to provide a comprehensive review of agricultural multispectral research in terms of research areas, institutions, influential journals, and core authors. Results of the analysis show that the number of publications increased each year, with the largest increase in 2019. Remote sensing, imaging technology, environmental science, and ecology are the most popular research directions. The journal Remote Sensing is one of the most popular publishers, showing a high publishing potential in multispectral research in agriculture. The institution with the most research literature and citations is the USDA. In terms of the number of papers, Mtanga is the author with the most published articles in recent years. Through keyword co-citation analysis, it is determined that the main research areas of this topic focus on remote sensing, crop classification, plant phenotypes and other research areas. The literature co-citation analysis indicates that the main research directions concentrate in vegetation index, satellite remote sensing applications and machine learning modeling. There is still a lot of room for development of multi-spectrum technology. Further development can be carried out in the areas of multi-device synergy, spectral fusion, airborne equipment improvement, and real-time image processing technology, which will cooperate with each other to further play the role of multi-spectrum in agriculture and promote the development of agriculture.

ICA II Alleviates Testicular Torsion Injury by Dampening the Oxidative and Inflammatory Stress.

Testicular torsion-detorsion is an ischaemia-reperfusion-induced male gonad injury that may lead to male infertility. Oxidative stress plays an important role in the ischaemia-reperfusion injury. Icariside II (ICA II) prevents oxidative stress and has obvious protective effects on spermatogenic function. The present study was aimed to investigate therapeutic potentials of ICA II on testicular torsion. 72 mice were randomly divided into three groups: sham-operated control group (n = 24), testicular ischemia-reperfusion + saline group (n = 24) and testicular ischemia-reperfusion + icariside II treated group (n = 24). Testicular ischemia-reperfusion was induced by the left testis rotated 360 degrees in a clockwise direction for 30 minutes followed by detorsion, the contralateral testis was removed. ICA II in saline (5 mg/kg/day) was administrated by gavage immediately after detorsion. The results demonstrated that ICA II alleviated testicular damage by mitigating spermatogenic cell injury and improving testosterone production in mouse models of testicular torsion. We revealed that ICA II alleviated oxidative stress and apoptosis in the testes, reduced inflammatory infiltration and accelerated angiogenesis. Briefly, ICA II administration ameliorated testicular damage by improving spermatogenic function and testosterone production, which supports its use as a pharmacological treatment of testicular torsion.

IL-1ß-primed mesenchymal stromal cells exert enhanced therapeutic effects to alleviate Chronic Prostatitis/Chronic Pelvic Pain Syndrome through systemic immunity.

BACKGROUND: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) seriously affects patient health. Despite the elusiveness of innate therapeutic effects, mesenchymal stromal cells (MSCs) hold great promise for inflammation-related diseases. Recent evidence indicates that disease-specific inflammatory cytokines could enhance the therapeutic effects of MSCs. METHODS: By establishing a CP/CPPS mouse model and pretreating MSCs with the cytokine interleukin-1ß (IL-1ß), we studied the IL-1ß-primed MSC immunoregulatory ability and targeted migration ability in vitro and in CP/CPPS mice. RESULTS: IL-1ß levels significantly increased in the prostate tissue and serum of experimental autoimmune prostatitis (EAP) mice. Pretreatment with IL-1ß enhanced the immunomodulatory potential and targeted migration of MSCs in vitro. Furthermore, intravenous infusion of IL-1ß-primed MSCs dampened inflammation in prostate tissues and alleviated hyperalgesia in EAP mice. The infused MSCs inhibited monocyte infiltration and promoted regulatory T lymphocyte formation in prostate tissue, thus remodeling the local environment. Surprisingly, IL-1ß-primed MSCs exhibited improved accumulation in the spleen but not in prostate tissue. Accordingly, infused MSCs reshaped systemic immunity by reducing the proportion of Ly6ChighCD11b+ monocytes and boosting the proportion of CD4+Foxp3+ regulatory T lymphocytes in the spleen and lung. Inflammatory chemokine (C-C motif) ligand 2 (CCL2) decreased through the downregulation of the NF-κB and JNK/MAPK pathways by inflammatory resolution via MSCs infusion to alleviate pain. CONCLUSION: In summary, IL-1ß-primed MSCs restored systemic immunologic homeostasis to alleviate CP/CPPS by modulating systemic immunity. These findings provide a novel strategy to boost the therapeutic effects of MSC-based therapy for CP/CPPS and reveal the essential role of systematic immunity in the treatment of CP/CPPS with MSC infusion.

Stem cell-based therapies for fertility preservation in males: Current status and future prospects.

With the decline in male fertility in recent years, strategies for male fertility preservation have received increasing attention. In this study, by reviewing current treatments and recent publications, we describe research progress in and the future directions of stem cell-based therapies for male fertility preservation, focusing on the use of spermatogonial stem cells (SSCs), SSC niches, SSC-based testicular organoids, other stem cell types such as mesenchymal stem cells, and stem cell-derived extracellular vesicles. In conclusion, a more comprehensive understanding of the germ cell microenvironment, stem cell-derived extracellular vesicles, and testicular organoids will play an important role in achieving male fertility preservation.

Impact on using cryopreservation of testicular or epididymal sperm upon intracytoplasmic sperm injection outcome in men with obstructive azoospermia: a systematic review and meta-analysis.

PURPOSE: To determine whether there was a significant impact on using cryopreservation of testicular or epididymal sperm upon the outcomes of intracytoplasmic sperm injection (ICSI) in patients with obstructive azoospermia (OA). METHOD: Systematic review and meta-analysis of 20 retrospective studies in databases from January 1, 1995, to June 1, 2020. RESULT: Twenty articles were included in this study. A total of 3602 (64.1%) of 5616 oocytes injected with fresh epididymal sperm were fertilized, compared with 2366 (61.2%) of 3862 oocytes injected with cryopreserved sperm (relative risk ratio (RR) 0.96, 95% confidence interval (CI) (0.90, 1.02), P > 0.05). A total of 303 (44.1%) of 687 ICSI cycles using fresh epididymal sperm resulted in a clinical pregnancy, compared with 150 (36.6%) of 410 ICSI cycles using cryopreserved epididymal sperm (RR 0.84, 95% CI (0.72, 0.97), P < 0.05). In the testis, a total of 2147 (68.7%) of 3125 oocytes injected with fresh sperm were fertilized, compared with 1623 (63.5%) of 2557 oocytes injected with cryopreserved sperm (RR 0.97, 95% CI (0.90, 1.06), P > 0.05). A total of 151 (47.8%) of 316 ICSI cycles using fresh testicular sperm resulted in a clinical pregnancy, compared with 113 (38.2%) of 296 ICSI cycles using cryopreserved sperm (RR 0.87, 95% CI (0.72, 1.05), P > 0.05). CONCLUSIONS: In men with OA, there was a statistical lower clinical pregnancy rate (CPR) by using frozen epididymal sperm compared with fresh epididymal sperm, but showing no difference on fertilization rate (FR). Additionally, FR and CPR were not affected by whether the retrieved testicular sperm was frozen or fresh.

Comparative efficacy and safety of drug treatment for premature ejaculation: A systemic review and Bayesian network meta-analysis.

To assess the comparative efficacy and safety of drug treatments for premature ejaculation. A systemic review and Bayesian network meta-analysis were executed on randomised controlled trials of drug interventions for premature ejaculation. Intravaginal ejaculation latency time and related adverse effects were outcome measures. A total of 44 RCTs with 11,008 patients were included in our NMA. In therapy <8 weeks, the ranking of drug efficacy was topical creams >selective serotonin reuptake inhibitor (SSRI)+ phosphodiesterase 5 inhibitor (PDE5i) > PDE5i > sertraline > clomipramine > paroxetine > dapoxetine 60 milligram (mg) > dapoxetine 30 mg > fluoxetine>citalopram > duloxetine>placebo. In therapy ≥ 8 weeks, the ranking of drug efficacy was SSRI + PDE5i > topical creams > paroxetine > tramadol > PDE5i > fluoxetine > dapoxetine 60 mg > dapoxetine 30 mg > clomipramine>citalopram > placebo. For total adverse events, clomipramine, dapoxetine 30 mg, dapoxetine 60 mg, paroxetine, PDE5i, SSRI + PDE5i and tramadol had a higher risk than placebo. In conclusion, in ≥8 weeks of therapy, the drug combination of SSRI + PDE5i was the most effective PE therapy. In <8 weeks of therapy, the efficacy of local anaesthetics was best. All drug treatments were ranked better than placebo. In general, drugs with better effects had more obvious side effects.

Room-temperature autonomous self-healing glassy polymers with hyperbranched structure.

Glassy polymers are extremely difficult to self-heal below their glass transition temperature (T g) due to the frozen molecules. Here, we fabricate a series of randomly hyperbranched polymers (RHP) with high density of multiple hydrogen bonds, which show T g up to 49 °C and storage modulus up to 2.7 GPa. We reveal that the hyperbranched structure not only allows the external branch units and terminals of the molecules to have a high degree of mobility in the glassy state, but also leads to the coexistence of "free" and associated complementary moieties of hydrogen bonds. The free complementary moieties can exchange with the associated hydrogen bonds, enabling network reconfiguration in the glassy polymer. As a result, the RHP shows amazing instantaneous self-healing with recovered tensile strength up to 5.5 MPa within 1 min, and the self-healing efficiency increases with contacting time at room temperature without the intervention of external stimuli.

Primary sarcomatoid urothelial carcinoma of the ureter: a case report and review of the literature.

BACKGROUND: Sarcomatoid urothelial carcinoma is a very dangerous malignant tumour derived from the epithelium. Primary sarcomatoid carcinoma of the ureter is extremely rare in clinical practice. The prognosis of this kind of disease is really poor, and there is still not a diagnosis standard in the world. CASE PRESENTATION: An 82-year-old female patient who had intermittent waist pain without any other symptoms, had diagnosed as urothelial cancer on computerised tomography urography. Considering the patient's age and quality of life, we made a preserving kidneys resection of the local tumour. The tumour was composed of sarcomatous and carcinomatous elements, and immunohistochemical examination showed that tumour cells were positive for cytokeratin, epithelial membrane antigen, vimentin, and GATA3 markers. There were no complications after 1-hour surgery. After 3 months, there was no signs of recurrence and metastasis. CONCLUSION: This case was a patient with sacomatoid urothelial carcinoma. Through a transurethral resection with laser, the patient recovered well, and there was no sign of any recurrence of the tumour after 3 months. With the development of technology and science, more and more cancerous patients' living quality and survival rate were improved. Maybe it is essential for urologists and scientists to entirely understand the characteristics of the sarcomatoid urothelial carcinoma and make a better clinical guideline.

Simultaneous reinforcement and toughness improvement of an epoxy-phenolic network with a hyperbranched polysiloxane modifier.

An epoxy-phenolic network is modified with hyperbranched polysiloxane (HBPSi). The addition of HBPSi-2, which has medium molecular weight, can significantly decrease the viscosity of the uncured epoxy-phenolic system and increase the crosslinking density and homogeneity of the cured crosslinking network. With 10% HBPSi-2, the mechanical properties of the samples are improved comprehensively: tensile modulus and maximum strength increase by 11.4% and 36.2%, respectively, while elongation at break and impact strength increase by 153.8% and 186.7%, respectively. The comprehensive improvements in the mechanical properties are attributed to combined effects of crosslinking density, network rigidity, cohesive density and the matrix-modifier compatibility. What is more, HBPSi-2 also significantly increases the char yield of the material and decreases the thermal weight loss rate, indicating an improved thermal stability. All these results may provide a new strategy for toughness and strength improvement of the epoxy-phenolic network.

CIFAR10-DVS: An Event-Stream Dataset for Object Classification.

Neuromorphic vision research requires high-quality and appropriately challenging event-stream datasets to support continuous improvement of algorithms and methods. However, creating event-stream datasets is a time-consuming task, which needs to be recorded using the neuromorphic cameras. Currently, there are limited event-stream datasets available. In this work, by utilizing the popular computer vision dataset CIFAR-10, we converted 10,000 frame-based images into 10,000 event streams using a dynamic vision sensor (DVS), providing an event-stream dataset of intermediate difficulty in 10 different classes, named as "CIFAR10-DVS." The conversion of event-stream dataset was implemented by a repeated closed-loop smooth (RCLS) movement of frame-based images. Unlike the conversion of frame-based images by moving the camera, the image movement is more realistic in respect of its practical applications. The repeated closed-loop image movement generates rich local intensity changes in continuous time which are quantized by each pixel of the DVS camera to generate events. Furthermore, a performance benchmark in event-driven object classification is provided based on state-of-the-art classification algorithms. This work provides a large event-stream dataset and an initial benchmark for comparison, which may boost algorithm developments in even-driven pattern recognition and object classification.

Differences in the Vibrational Dynamics of H(2)O and D(2)O: Observation of Symmetric and Antisymmetric Stretching Vibrations in Heavy Water.

Water's ability to donate and accept hydrogen bonds leads to unique and complex collective dynamical phenomena associated with its hydrogen-bond network. It is appreciated that the vibrations governing liquid water's molecular dynamics are delocalized, with nuclear motion evolving coherently over the span of several molecules. Using two-dimensional infrared spectroscopy, we have found that the nuclear motions of heavy water, D2O, are qualitatively different than those of H2O. The nonlinear spectrum of liquid D2O reveals distinct O-D stretching resonances, in contrast to H2O. Furthermore, our data indicates that condensed-phase O-D vibrations have a different character than those in the gas phase, which we understand in terms of weakly delocalized symmetric and antisymmetric stretching vibrations. This difference in molecular dynamics reflects the shift in the balance between intra- and intermolecular couplings upon deuteration, an effect which can be understood in terms of the anharmonicity of the nuclear potential energy surface.

Quantum Local Monomer IR Spectrum of Liquid D2O at 300 K from 0 to 4000 cm(-1) Is in Near-Quantitative Agreement with Experiment.

The local monomer model is applied, with ab initio potential energy and dipole moment surfaces, to a calculation of the IR spectrum of liquid D2O at 300 K, over the spectral range 0 to 4000 cm(-1). The spectrum is an incoherent superposition of spectra of many monomers over snapshots of a molecular dynamics trajectory, where both intramolecular and intermolecular coupling in each monomer is treated. The comparison to experiment shows an unprecedented level of agreement for the stretch, bend, and libration bands and also the bend+libration and stretch+bend combination bands. This indicates that the incoherent approach captures much of the dynamics underlying the spectrum, provided monomer couplings are considered. The calculated spectrum is compared to the recently calculated IR spectrum of H2O, using the same method and potential energy and dipole moment surfaces, and shifts relative to that spectrum are presented and discussed.

Transferable ab Initio Dipole Moment for Water: Three Applications to Bulk Water.

We recently reported a second-generation, ab initio dipole moment surface (DMS) for water and applied it successfully to the IR spectrum of liquid water at 300 K. Here the transferability of this DMS is demonstrated in three applications. One is the distribution of monomer dipole moments, considering two definitions, and effective atomic charges of liquid water at 300 K and also for a model of ice Ih at 0 K. The second one is a calculation of the dielectric constant of liquid water at 280, 300, 320, 340, 360 K, and the third one is correcting the intensities of the IR spectrum of liquid water at 300 K, obtained using the q-TIP4P/F potential, bringing them into much improved agreement with experiment. For the purpose of obtaining statistical ensembles we use molecular dynamics simulations with the TIP4P+E3B water model developed by Skinner and co-workers. The average monomer dipole moments for 300 K water and 0 K ice Ih are 2.94 and 3.54 D, respectively, in good agreement with literature values. Effective monomer charge distributions are derived from the monomer dipoles and give average values of -1.02 e for O and 0.51 e for H in liquid water, which are also in agreement with values reported from experiment. The calculated dielectric constant of liquid water at the above five temperatures is compared to experiment and is roughly 10-15% lower than experiment.

Ab Initio Quantum Approaches to the IR Spectroscopy of Water and Hydrates.

This Perspective highlights progress in ab initio quantum approaches to IR spectroscopy of water and hydrates. Here, "ab initio" refers to many-body potentials and dipole moment surfaces for flexible water and hydrates. Specifically, these are mathematical representations of two-body and three-body interactions based on permutationally invariant fitting of tens of thousands of ab initio electronic energies, a spectroscopically accurate one-body monomer potential, and four- and higher-body interactions described by the long-range interactions incorporated into, for example, the TTM3-F family of potentials. There are currently two such potentials of this type, denoted WHBB and MB-pol, which are being used in expanding applications. Here, the focus is on infrared spectroscopy, using the WHBB potential and dipole moment surface, with an embedded, local monomer quantum method to obtain vibrational energies and dipole transition moments. Comparisons are also made with the popular q-TIP4P/F potential. Brief mention is made of an application to small HCl-H2O clusters.

Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment.

The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H2O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0-4000 cm(-1) is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band.

Communication: On the consistency of approximate quantum dynamics simulation methods for vibrational spectra in the condensed phase.

Including quantum mechanical effects on the dynamics of nuclei in the condensed phase is challenging, because the complexity of exact methods grows exponentially with the number of quantum degrees of freedom. Efforts to circumvent these limitations can be traced down to two approaches: methods that treat a small subset of the degrees of freedom with rigorous quantum mechanics, considering the rest of the system as a static or classical environment, and methods that treat the whole system quantum mechanically, but using approximate dynamics. Here, we perform a systematic comparison between these two philosophies for the description of quantum effects in vibrational spectroscopy, taking the Embedded Local Monomer model and a mixed quantum-classical model as representatives of the first family of methods, and centroid molecular dynamics and thermostatted ring polymer molecular dynamics as examples of the latter. We use as benchmarks D2O doped with HOD and pure H2O at three distinct thermodynamic state points (ice Ih at 150 K, and the liquid at 300 K and 600 K), modeled with the simple q-TIP4P/F potential energy and dipole moment surfaces. With few exceptions the different techniques yield IR absorption frequencies that are consistent with one another within a few tens of cm(-1). Comparison with classical molecular dynamics demonstrates the importance of nuclear quantum effects up to the highest temperature, and a detailed discussion of the discrepancies between the various methods let us draw some (circumstantial) conclusions about the impact of the very different approximations that underlie them. Such cross validation between radically different approaches could indicate a way forward to further improve the state of the art in simulations of condensed-phase quantum dynamics.