Searching for Heavy Dark Matter near the Planck Mass with XENON1T.

Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17} GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.

First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment.

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03) ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3) events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47} cm^{2} for a WIMP mass of 28 GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

Search for New Physics in Electronic Recoil Data from XENONnT.

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

Plastic does not simply flow into the sea: River transport dynamics affected by tides and floating plants.

Plastic pollution is ubiquitous in aquatic environments worldwide. Rivers connect terrestrial and marine ecosystems, playing a key role in the transport of land-based plastic waste towards the sea. Emerging research suggests that in estuaries and tidal rivers, tidal dynamics play a significant role in plastic transport and retention dynamics. To date, observations in these systems have been limited, and plastic transport dynamics during single tidal cycles remain poorly understood. Here, we investigated plastic transport, trapping, and re-mobilization of macroplastics (> 0.5 cm) in the Saigon River, focusing on short-term dynamics of individual tidal cycles. We used GPS trackers, released at different stages of the tidal cycle (ebb, flood, neap, spring). Plastic items demonstrated dynamic and intermittent transport behavior. Items spent almost half of the time (49%) temporarily stopped, mainly due to their entrapment in vegetation, infrastructure, or deposition on riverbanks. Items were almost always re-mobilized within 10 h (85%), leading to successive phases of stopping and transport. Tidal dynamics also resulted in bidirectional transport of plastic items, with median daily total transport distance within the 40 km study reach (8.9 km day-1) over four times larger than the median daily net distance (2.0 km day-1). The median retention time of plastic items within the reach was 21 days (mean = 202 days). In total, 81% of the retrieved items were trapped within water hyacinths, emphasizing the important role of floating vegetation on river plastic transport dynamics. With this paper, we aim to provide data-driven insights into macroplastic transport and retention dynamics in a tropical tidal river. These are crucial in the design of effective intervention and monitoring strategies, and estimating net plastic emission from rivers into the sea.

In vitro anti-leukemia, antioxidant, and anti-inflammatory properties of Lantana camara.

It has been demonstrated that Lantana camara possesses several therapeutic properties that can be used to treat various human diseases, including dermatological and gastrointestinal conditions, tetanus, malaria, and tumours. In this investigation, every collected part of L. camara was extracted with absolute methanol to examine its antioxidant capacity using the DPPH assay and its anti-leukemia activity on two AML cell lines, MOLM-13 and MV4-11. In addition, anti-inflammatory effectiveness was evaluated. The results show that extracts from various sections of L. camara have a significant ability to neutralize free radicals, as indicated by their EC50 values. Most of the extracts had values less than 100 µg/ml, with the flower extract having an even lower value of less than 50 µg/ml. Experiments on two AML cell lines showed that the anti-leukemia effects of the extracts were remarkable, with the most potent impact belonging to the root extract (IC50 was 9.78 ± 0.61 and 12.48 ± 1.69 for MOLM-13 and MV4-11 cell lines). The antitumor effect of the extracts was determined to be time- and dose-dependent and did not correlate with antioxidant capacity. Furthermore, when BJ cells were exposed to L. camara root and leaf extracts, their migratory potential was dramatically reduced compared to untreated cells. The extracts demonstrated potential anti-inflammatory capabilities by lowering NO production in LPS-induced BJ cells.

White hard clam (Meretrix lyrata) shells media to improve phosphorus removal in lab-scale horizontal sub-surface flow constructed wetlands: Performance, removal pathways, and lifespan.

This work examined the phosphorus (P) removal from the synthetic pretreated swine wastewater using lab-scale horizontal sub-surface flow constructed wetlands (HSSF-CWs). White hard clam (Meretrix lyrata) shells (WHC) and Paspalum atratum were utilized as substrate and plant, respectively. The focus was placed on treatment performance, removal mechanisms and lifespan of the HSSF-CWs. Results indicated that WHC-based HSSF-CW with P. atratum exhibited a high P removal (89.9%). The mean P efluent concentration and P removal rate were 1.34 ± 0.95 mg/L and 0.32 ± 0.03 g/m2/d, respectively. The mass balance study showed that media sorption was the dominant P removal pathway (77.5%), followed by microbial assimilation (14.5%), plant uptake (5.4%), and other processes (2.6%). It was estimated the WHC-based bed could work effectively for approximately 2.84 years. This WHC-based HSSF-CWs technology will therefore pave the way for recycling Ca-rich waste materials as media in HSSF-CWs to enhance P-rich wastewater purification.

Novel activation of gamma-interferon in nonimmune cells during human cytomegalovirus replication.

This is the first study documenting the induction of gamma-interferon (IFN-gamma) in human embryonic fibroblasts during human cytomegalovirus (HCMV) replication. Infection of cells with HCMV resulted in the consistent production of IFN-gamma RNA, as determined by RT-PCR and Northern blot analysis. Western blot analysis of cell lysates and immunoprecipitates from the cultural fluids of infected cells demonstrated the presence of IFN-gamma at the protein level. Induction of IFN-gamma required infectious HCMV, since high-dose ultraviolet inactivation of the virus stock eliminated IFN-gamma production. Further, IFN-gamma induction appears to be a late event in the virus replication cycle, since inhibition of HCMV DNA synthesis (e.g., phosphonoacetic acid) blocked the increase in IFN-gamma. Soluble factor(s) released from HCMV-infected cells apparently did not contribute to the induction of IFN-gamma, since virus stocks from which virus had been removed by sedimentation did not induce production of IFN-gamma. The appearance of IFN-gamma at late stages of HCMV infection and its elimination in the presence of an inhibitor (Actinomycin D) of RNA synthesis indicate a true transcriptional induction of this lymphokine at the RNA and protein levels. The significance of IFN-gamma production with regard to the replication and pathogenesis of HCMV in vitro and in vivo will require further investigation.

Production of interferon gamma messenger RNA by cells of non-immune origin.

There is general agreement that IFN-gamma is produced only by cells of immune origin (T-cells, NK cells, and recently macrophages). However, indirect evidence has suggested that undetectable, low levels of IFN-gamma produced by cells of non-immune lineage, such as the murine line L-929, enhanced the antiviral activity of IFNs-alpha and/or beta following induction by agents such as the double stranded RNA poly ICLC. Since L-929 cells were one of the prototypic cell lines for studying murine IFN induction and action, we felt that it would be important to validate this observation by detection of the mRNA for IFN-gamma. If confirmed, it might indicate a role for IFN-gamma in non-immune cells. The present investigations revealed that mouse L-929 fibroblasts produce IFN-gamma message following exposure to conventional IFN-alpha/beta inducers such as poly ICLC or Newcastle disease virus. In addition, we found that IFN-gamma itself will induce its own message. We further show that this is not a phenomenon isolated to transformed cells since we found that normal mouse embryo fibroblasts also produced the message, however in a constitutive fashion.