Antibiotic resistance (AMR) is a global health crisis responsible for over five million deaths annually. Rapid antimicrobial susceptibility testing (RAST) is critical for timely clinical decision-making. This study develops a hydrogel-based 3D culture microfluidic platform enclosed within a PMMA box, enabling safe and rapid testing of highly pathogenic bacteria. The microfluidic chip employs a Christmas tree concentration gradient generator, capable of simultaneously delivering four distinct drug concentrations. Theoretical, finite-element method, and experimental analyses demonstrated precise gradient control by tuning inlet flow-rate ratios (Q1/Q0), concentration ratios (C0/C1), and absolute concentrations (C0). Optimizing hydrogel porosity (90%) and chamber height (200 μm) enhanced mass transfer, improving bacterial growth and drug delivery. Using Escherichia coli ATCC 25922 as a model, the system determined the minimum inhibitory concentration (MIC, 2 μg/mL) of gentamicin within 2 h─8 to 10-fold faster than standard methods, while matching conventional AST accuracy. From a fluid dynamics perspective, this work optimized the flow and mass transfer processes in AST, thereby enhancing the contact between nutrients, drugs, and bacteria. This hydrogel-based 3D microfluidic system provides a safe, efficient, and scalable RAST platform with strong potential for clinical applications against highly pathogenic and drug-resistant bacteria.

Lipomyelomeningocele is a complex form of closed spinal dysraphism characterized by a lipomatous mass tethered to the spinal cord, protruding through a neural tube defect. This report details the MRI findings of an 11-year-old female presenting with significant lumbosacral abnormalities, a tethered cord, and secondary urological manifestations including a "Christmas tree" bladder.

Lipomyelomeningocele is a complex form of closed spinal dysraphism characterized by a lipomatous mass tethered to the spinal cord, protruding through a neural tube defect. This report details the MRI findings of an 11-year-old female presenting with significant lumbosacral abnormalities, a tethered cord, and secondary urological manifestations including a "Christmas tree" bladder.

Although uncommon in the general population, jejunoileal atresia (JIA) is a common cause of intestinal obstruction in infants. This congenital anomaly may cause a substantial reduction in intestinal length, enhancing the likelihood of short bowel syndrome and intestinal failure. A Christmas tree anomaly is an uncommon form of JIA, accounting for 5%-10% of all small intestinal atresia. A preterm male infant was admitted at our setting with signs of intestinal obstruction. The patient had features of proximal obstruction from abdominal x-ray results, prompting surgery. A jejunal atresia of type IIIb was ascertained intraoperatively. The surgical correction involved a primary anastomosis. He initially recovered well postoperatively and tolerated oral meals; nevertheless, his condition deteriorated, terminating in a fatal cardiac arrest. Our patient had multiple predisposing characteristics, notably a postoperative respiratory compromise, which exacerbated the prognosis. As such, improving neonatal care as well as adopting an early approach to managing these patients is critical for improving their prognosis.

Christmas tree growers are concerned with improving establishment of their plantations. Here, we report the results of a series of on-farm trials conducted with grower-cooperators in the Pacific Northwest (PNW) and Great Lakes (Michigan—MI) regions to determine the efficacy of treatments at planting on improving tree survival and growth in Christmas tree plantations. Cooperating growers planted species that were typical for each region (Fraser fir in the Great Lakes and Douglas-fir and noble fir in the PNW) and managed the plantings using standard cultural practices, aside from test treatments. Test treatments varied between locations and years but included wood chip mulch, shade blocks, an anti-transpirant, biochar, fertilizers, and various root dips including polymer gels, mycorrhizae, and bio-stimulants. Overall, treatments that directly modified the tree environment (i.e., mulch and shade blocks) provided the most consistent benefit to tree survival and growth. In Michigan, mulching increased survival by 5% on non-irrigated farms and increased second-year shoot growth by ~3 cm. In the PNW trials, mulching increased survival of noble fir seedlings more than Douglas-fir seedlings. Installing controlled release fertilizer packets at planting increased initial growth of Douglas-firs. Application of root dips prior to planting did not improve tree survival or growth relative to dipping tree roots in water (control). Based on our results, we conclude that treatments that conserve soil moisture (mulch) or reduce tree water loss (shade blocks) offer the most direct opportunity for growers to improve initial tree survival and growth.

To address the failure risks associated with long-term service of subsea Christmas tree-wellhead systems under the complex marine environment of the South China Sea, a multi-factor coupled mechanical analysis method is proposed to evaluate the system’s mechanical characteristics and ensure the safety of deepwater oil and gas production. A dynamic model of lateral vibration under seismic loading is established, considering the combined effects of earthquakes, ocean currents, and seabed soil resistance. Based on the actual operating parameters of a well in the Lingshui area of the South China Sea, a three-dimensional finite element model of the subsea Christmas tree-wellhead assembly was developed in ABAQUS 2023. The combined effects of ocean currents, seismic loading, and corrosion over long-term service were simulated to compute and analyze the distributions of stress, bending moment, and associated failure risk. The results indicate that, under a once-in-a-century current combined with seismic waves of intensity V–VI, the system risk remains controllable. However, when the seismic intensity exceeds level VII, the maximum stress and bending moment reach 324.9 MPa and 6.02 MN·m, respectively, surpassing the allowable limits for an X56-grade surface conductor. Considering corrosion effects over a 25-year service life, the extreme stress values increase by 1–5% while the bending moment increases slightly; corrosion significantly amplifies the system’s failure risk. An analysis of the mudline burial height of the subsea wellhead during long-term service shows that, within a range of 1–7 m, variations in system loading are minimal. Based on the mechanical characteristics analysis, it is recommended that the design of subsea Christmas trees and wellheads incorporate regional seismic history, specify X56-grade surface conductors to mitigate corrosion effects, and install leakage-monitoring devices at critical locations to ensure the long-term service safety of the subsea Christmas tree-wellhead system.

Abstract Common ragweed ( Ambrosia artemisiifolia L.) is a globally distributed, difficult to control weed that can cause severe crop yield losses if not properly managed. Clopyralid is a synthetic auxin herbicide widely used to control A. artemisiifolia and other Asteraceae weeds. In 2016, a highly clopyralid resistant A. artemisiifolia population was reported on a Michigan Christmas tree farm which we call AMBEL-40. We investigated the inheritance and potential clopyralid resistance mechanisms in this population using greenhouse dose response assays, test crosses with a susceptible line - AMBEL-39, and RNA-seq. The ED 50 values for AMBEL-40 and AMBEL-39 were 2,110.8 and 74.5 g ha -1 , respectively; therefore, the R/S ratio is 28.3. Dose response results with triclopyr, fluroxypyr, 2,4-D, or dicamba demonstrate no multiple or cross-resistance in AMBEL-40. AMBEL-40 and AMBEL-39 crossed F 1 generations (M3F1, M3F2, and M1F1) showed increased resistance compared to AMBEL-39 with ED 50 values of 1,379.2, 1,134.0, and 542.5 g ha -1 . Chi-square tests of three sib-mated F 1 to generate F 2 generations rejected a single-gene 1:3 model and supported a two-gene 3:13 segregation, consistent with multigenic inheritance. We identified 23 Aux/IAA transcripts containing the degron sequence in the published Ambrosia artemisiifolia genome, of these, three contained polymorphisms in our RNAseq data, but none consistently co-segregated with resistance. Differential expression analysis identified 70 genes with 39 upregulated and 31 downregulated in AMBEL-40 including candidates in auxin/ethylene signaling, metabolism, cuticular wax biosynthesis, and stress modulation, supporting a non-target site resistance mechanism. Together, these results indicate that clopyralid resistance in A. artemisiifolia is recessive, and multigenic, with potentially altered signaling, metabolism, and uptake as a mechanism of resistance rather than a single Aux/IAA degron mutation.

During deepwater completion and testing, the platform and riser system are subjected to long-term motions induced by ocean currents, which may cause structural damage and potential failure of the landing string. This study investigates the mechanical and fatigue performance of a subsea Christmas tree and landing string under environmental conditions of the LH11-1 Oilfield in the South China Sea. A global–local simulation framework is used to build a coupled dynamic model of the riser–landing string system and a local model for the landing string, considering load-transfer characteristics, current profiles, periodic features, and two representative environmental conditions (typhoon and non-typhoon). For seventeen typical operating scenarios, the strength of the riser–landing string system is evaluated, and wave-induced and vortex-induced fatigue analyses are performed for the key components. The stress distribution strongly depends on operating conditions, but local strength results confirm that stresses in the primary landing string components remain below allowable limits in all scenarios. Fatigue analysis indicates that the most severe wave-induced damage in the riser occurs at its bottom section, with a fatigue life of about 15.12 years, while in the landing string, it is concentrated near the lower end, with an estimated life of about 52.68 years. The maximum vortex-induced fatigue damage occurs near the riser surface region, with a corresponding fatigue life of about 18.52 years.

Balsam fir is an important specialty horticultural crop in eastern North America and commonly harvested for use as Christmas trees. Postharvest quality is a major challenge for producers, who are particularly concerned about postharvest needle retention. It was hypothesized that pyroligneous acid (PA) would help increase postharvest needle retention in balsam fir when supplied via xylem or foliage. This project first identified foliar spraying as the best application method, then designed a multivariate experiment with two factors. The first factor was foliar treatment (control, water, 1% PA, 2% PA, and 4% PA). The second factor was time, where branches were evaluated for needle abscission at 0, 2, 4, 6, and 8 weeks after harvest. The experiment was replicated 5 times and needle abscission, water uptake, chlorophyll, carotenoids, flavonoids, total phenolics, membrane injury, proline, and H2O2 production were all measured in response. Postharvest abscission reached 100% over the 8-week experiment and water uptake decreased by over 80%. Chlorophyll, proline, membrane injury, and H2O2 production all increased over time. Although PA did not improve needle retention compared to the control under the tested conditions, 4% PA spray increased proline concentration by 40% while decreasing membrane injury by 26%. Ultimately, PA did not consistently improve needle retention but did induce proline accumulation and membrane protection.

The article is devoted to Sasha Cherny’s latest author’s collections for children, published in exile: “The Silver Christmas Tree” (1929), “The Ruddy Book” (1930) and “The Seafaring Squirrel” (1933). The purpose of this work is to determine the author’s approach of Sasha Cherny to the formation of books for children. The following conclusions were reached during the study: the first works that open the collection can be called programmatic, since they set the main theme, images, and motifs. Each collection is based on different author’s approaches, the leading principle of unity is different: genre, thematic and artistic images. Each collection has its own themes, but there are common ones as well, such as motifs of joy and play. These define the tone of Sasha Cherny’s works for children, where all conflicts and dangerous situations are resolved happily. There is a special author’s narrative style: in some works, events are shown from the perspective of other beings, when the narrator provides a voice to his characters and animals or toys become the subjects of the focus. In some, on the contrary, the narrator’s voice and a special warm intonation are heard, which betrays the author’s attitude towards his characters: sympathy and empathy, irony or humor that relieves tension and sets the mood for a successful resolution of a difficult or dangerous situation. The collections Serebryanaya Yelka (The Silver Christmas Tree), Rumyanaya Knizhka (The Ruddy Book), Belka-moreplavatel’nitsa (The Seafaring Squirrel), and became the last Sasha Cherny’s books for children, in which the writer recalled his early work, told young readers about Russia, and delighted with the funny stories of his contemporaries.

The Christmas tree faces significant safety risks during installation and requires extremely high reliability during operation. In this study, a comprehensive risk assessment method combined GA-BP neural network and improved HAZOP method is established, which is the first application used in the field of risk analysis for offshore oil equipment. The sample risk data during the installation and operation of the China’s first domestically produced Christmas tree is extracted through multi-source fusion, and the possibility and severity levels of risk occurrence are classified and judged. By training and testing the model it shows that the average error rate of the proposed GA-BP multi-source information fusion method is only 5.10%. Through risk data extraction and evaluation, the failure probability when the Christmas tree lowering into water is found to be the highest, with a critical importance coefficient of 0.24. No high-risk failure modes are found during the production process, but there are 36 moderate risk points. Deep water gas well field testing shows the theoretical judgment is consistent with the actual discovery, and with using of hydrate inhibitor injection the blockage risk at the nozzle of the Christmas tree is alleviated, which verifying the accuracy of the method. The method has improved the risk warning system for the safe operation of the Christmas tree, and can provide technical support for similar subsea oil and gas production equipment.

Abstract Modern aircraft must meet stringent requirements related to, among other things, reducing the weight of their components whilst maintaining high strength and accuracy. Thin-walled integral elements are therefore widely used in aircraft structures. In industrial practice, however, their application poses a significant problem due to the susceptibility of these components to deformation, especially post-machining deformation, which becomes evident once the machining process is completed and the clamping force is removed. This is a very complex issue, and finding a comprehensive solution is complicated because of a large number of factors affecting the formation of post-machining deformation. This study investigates machining strategies in terms of post-machining deformation of thin-walled parts. Relationships are established between the residual stress in the surface layer of the material and the dimensional and shape accuracy of a thin-walled component made of aluminium alloys 2024 T351 and 7050 T7451. The machining strategies used in this study were the “Christmas tree” strategy and the hybrid strategy (combination of the “Christmas tree” strategy and milling of one side of the wall with constant axial and radial depths of cut). The cutting speed was also analysed. The results demonstrate that the post-machining deformation of thin-walled parts can be minimized by using a suitable machining strategy. An important finding is that it is possible to impact the residual stress in the surface layer of the material through milling strategy and cutting speed, leading to enhanced dimensional and shape accuracy of the thin-walled component. Better machining results in aspect of wall strain were obtained for the 7050 T7451 alloy.

Automated microscopy in forensic biology: Validating the use of deep neural networks for the detection of human spermatozoa in Christmas Tree stained slides.

Oil and gas equipment, during its operational lifespan, encounters a multitude of natural and technological influences, which subsequently alter its functional capabilities, thereby precipitating defects and failures. A principal contributor to the malfunctioning of the working surfaces within wellhead components, such as Christmas tree assemblies and gate valves, is wear, which is generated by elevated pressure and friction. Understanding wear's properties and working principles is vital for improving equipment reliability, extending its lifespan, and increasing operational efficiency. Recently, using nanoparticles has been a key area of research for improving tribological processes. Nanoparticle-based lubricant additives, nano-scale ceramic reinforcements, and high-hardness nanocomposite coatings like TiN, CrN, DLC, and AlTiN, reduce energy losses caused by friction, minimize micro-wear on contact surfaces, and improve mechanical durability. These nanotechnology solutions significantly enhance the tribological performance of contact zones in wellhead equipment, which leads to a longer operational lifespan. Studies exhibit that machinery with nanostructured surface coatings experiences less wear over time and maintains consistent mechanical properties, even when subjected to pressures as high as 105 MPa. The use of these nanostructured coatings helps to reduce early defects, improve the control of friction-related factors, and notably lower the chance of equipment failure. Keywords: christmas tree assembly, gate valve, tribological parameters, nanocomposite coatings, wear volume, wear rate

This study investigates the application of Smarandache product cordial labeling techniques to Christmas tree graphs. Graph labeling is a crucial aspect of graph theory, with applications in various fields such as computer science, coding theory, and network design. Smarandache product cordial labeling, in particular, offers a unique approach to labeling graphs while maintaining specific properties. By exploring the application of these techniques to Christmas tree graphs, this research aims to contribute to the understanding of graph labeling and its potential applications in real-world problems. The study presents theoretical results, algorithmic approaches, and potential extensions to related graph structures.

Coniferous species are known for their ability to purify air from particulate matter (PM), yet particulates accumulated during cultivation, transport, and outdoor storage may be transferred indoors. This study assesses the particulate load, subsequent retention, and further accumulation/release of PM by commercially available Christmas trees—Norway spruce (Picea abies (L.) H. Karst.) and Caucasian fir (Abies nordmanniana (Steven) Spach). Trees were examined in two commercial forms and maintained in six typical households (three with cut and potted P. abies, three with cut and potted A. nordmanianna) for 30 days. Measurements at four intervals included concentration dynamics of total PM, PM size fractions, as well as surface vs. in-wax PM ratios and epicuticular waxes on needles. Results showed that potted trees carried substantially higher initial PM loads than cut trees, with P. abies exceeding 200 µg·cm−2, likely due to differences in production and handling. Potted P. abies and cut A. nordmanniana retained large PM fractions more effectively than cut P. abies. In contrast, the fine PM fraction, the most health-relevant, was best accumulated by cut P. abies. Wax-bound PM shares increased time in potted trees and decreased in the cut. Overall, the findings suggest that choosing a Christmas tree is not only an aesthetic preference but a decision with measurable implications for winter indoor air quality.

Our study aims to analyze the unique forms of some folklore categories, and to approach the rites of the ceremonial-ritual acts of some particularizing circulation genres from the twelve-day cycle of Maramureș folklore. We first discussed the preparatory acts carried out for the great religious holidays of the previously mentioned cycle, and we focused on the ancient Christmas tree forms discovered during our field research in Codru area. We then talked about the preparation of ceremonial rolls, cooking of the meal etc. The investigation part consists in the analysis of the unique folklore genres of the cycle’s repertoire, and the analysis of the rites and of the particularizing ceremonial acts of the widely circulated folklore categories. In this section, we focused on the caroling custom in Codru area, with a rich content of rites and unique ceremonial acts, especially in the custom of carol singing performed by groups of young men. We then treated the original plays of the religious folk theater repertoire, but also of theater with historical subjects with original plays, which are individualized through particularizing elements. A section of our study was dedicated to the original masked folk dances, but also to events with particularizing elements of widely circulated masked dances: the Goat Dance and the Bear Dance.

In this article, F. Dostoevsky’s Christmas tale “The Beggar Boy at Christ’s Christmas Tree”, published in the Writer’s Diary in 1876 and sometimes referred to by scholars as a Christmas fairy tale, is examined in the context of two surrounding works – one text titled “A Boy with His Hand Stretched out for Alms” and another about a colony of juvenile delinquents. Although each of the three texts on the shared theme of child suffering is written in a different genre and style, together, they form a unified thematic block, combining elements of the journalistic, the fairy-tale, the Christian, and the documentary. The introduction of fairy-tale motifs into a literary work – which underlies the second, central part of the triptych about suffering children – is, from the author’s perspective, a distinctive artistic device through which the tragic motifs of the Christmas tale are further intensified, signaling the writer’s disbelief in the possibility of overcoming human suffering through the efforts of any magical helper, who is traditionally a hero of the fairy-tale genre. In this triptych, the conditional ‘fairy-tale lie’ is juxtaposed with the plot about a children’s colony, in which another, equally obscure yet more realistic motif of the salvation of the world is outlined.

Dancing around the Christmas tree combines physical activity with a full stomach and great emotions. This may lead to cardiac arrest. Previous studies have demonstrated that the rhythm in songs can support appropriate compression rates during cardiopulmonary resuscitation (CPR). The aim of this study was to investigate whether healthcare professionals can maintain high-quality CPR in a Christmas setting when exposed to Christmas songs with varying tempos (beats per minute, BPM) as a deliberate auditory distraction. This study was conducted at Prehospital South - EMS in Odense, Denmark, in a room decorated to resemble a Christmas Eve setting. Participants performed randomized two-minute CPR sessions on a Little Anne QCPR manikin while exposed to three Christmas songs of varying tempos: "Silent Night" (65 BPM), "Last Christmas" (110 BPM), and a Danish Christmas song with a BPM of 150 BPM. CPR quality was measured. Twenty-one participants completed the study. Compression depth was high across all three songs, with average scores ranging from 96% to 98%. Compression rate ranged between 108 and 110 BPM, with the highest proportion of time within the target range (100-120 BPM) observed during "Last Christmas" (79%) and the lowest during "Silent Night" (70%). Overall CPR scores were high (71-72%) with low variation. No statistically significant differences were found between the songs. Exposure to Christmas songs with varying tempos did not impact the quality of CPR among healthcare professionals, who maintained high-quality performance regardless of music choice. none. none.

ObjectivesTo test whether improving a Christmas tree meringue recipe using reporting guidelines yields more appealing and sweeter meringues.DesignA prospective, superiority, single-blind, cluster-randomised (1:1) controlled trial.SettingA public participatory event in a large cultural facility in France.ParticipantsBudding chefs with basic culinary skills, possessing the utensils necessary for baking Christmas tree meringues, and not having burned pasta in the past month (for safety reasons). Bunding chefs represent the cluster and meringue the unit.InterventionsEach budding chef was randomised to a standard recipe for making Christmas tree meringues or to the same recipe written in consultation with a professional baker using the TIDieR checklist—a reporting guideline for description of complex interventions—plus a short video tutorial.Main outcome measuresThe primary outcome was reproducibility in terms of visual aspect. Secondary outcomes included colour, size, taste and survival time in the course of a sale organised as part of the public event. The visual aspect, colour and size was rated by an independent jury which compared the cooked Christmas tree meringues with the recipe picture on a scale from 1 to 10. Analyses were performed in intention-to-eat (randomization unit: budding chefs / analysis unit: Christmas trees).Results60 budding chefs (30 in each group) baked a total of 845 Christmas tree meringues. There was no significant difference between the groups (mean difference = -0.1; [95%CI -0.99; 0.80]; p-value = 0.84; intra-cluster correlation, ICC = 0.77) on visual aspect. No difference was found for reproducibility in terms of colour (mean difference = -0.31; [95%CI -0.97; 0.35]; p-value = 0.35; ICC = 0.67) or size (mean difference = -0.17; [95%CI -1.07; 0.73]; p-value = 0.71; ICC = 0.74). There was no significant difference in terms of taste between the groups (mean difference = -0.55; [95%CI -1.62; 0.52]; p-value = 0.31). 400 meringues were sold during the public event with no difference in survival time between groups (hazard ratio = 1.26 [95% CI 0.75–2.09], p-value = 0.38, with values > 1 in favour of the control group). e.g. 75% survived for 134 min in intervention group and for 124 min in the control group.ConclusionsOur study failed to demonstrate that an improved recipe using the TIDieR reporting guideline with a video tutorial improved the reproducibility in terms of visual aspect, colour, size, taste and sales for Christmas tree meringues. The best way to succeed in reproducing Christmas tree meringues alike those showcased by the recipe—and thereby to improve reproducibility of experiments—remains a mystery still to be solved by further explorations.Trial registrationhttps://osf.io/dnhbx.Supplementary InformationThe online version contains supplementary material available at 10.1186/s41073-025-00167-x.