Canopy nitrogen deposition enhances soil ecosystem multifunctionality in a temperate forest.

Nitrogen (N) deposition affects ecosystem functions crucial to human health and well-being. However, the consequences of this scenario for soil ecosystem multifunctionality (SMF) in forests are poorly understood. Here, we conducted a long-term field experiment in a temperate forest in China, where N deposition was simulated by adding N above and under the canopies. We discover that canopy N addition promotes SMF expression, whereas understory N addition suppresses it. SMF was regulated by fungal diversity in canopy N addition treatments, which is largely due to the strong resistance to soil acidification and efficient resource utilization characteristics of fungi. While in understory N addition treatments, SMF is regulated by bacterial diversity, which is mainly because of the strong resilience to disturbances and fast turnover of bacteria. Furthermore, rare microbial taxa may play a more important role in the maintenance of the SMF. This study provides the first evidence that N deposition enhanced SMF in temperate forests and enriches the knowledge on enhanced N deposition affecting forest ecosystems. Given the divergent results from two N addition approaches, an innovative perspective of canopy N addition on soil microbial diversity-multifunctionality relationships is crucial to policy-making for the conservation of soil microbial diversity and sustainable ecosystem management under enhanced N deposition. In future research, the consideration of canopy N processes is essential for more realistic assessments of the effects of atmospheric N deposition in forests.

Cost-effectiveness analysis of pembrolizumab plus chemotherapy with PD-L1 test for the first-line treatment of NSCLC.

BACKGROUND: Pembrolizumab (Pembro) in combination with chemotherapy has been approved for the treatment of pretreated advanced NSCLC in the United States and China for its significant efficacy. However, the cost-effectiveness is unknown considering Pembro's high price. The impact of programmed death ligand 1 (PD-L1) test on the cost-effectiveness is also unknown. The current study assessed the cost-effectiveness of combination therapy for nonsquamous NSCLC from the United States and China public payers' perspective. MATERIALS AND METHODS: A literature-based Markov model was conducted using KEYNOTE-189 trial data to compare cost and quality-adjusted life years (QALYs) of three treatment strategies for nonsquamous NSCLC: Pembro-chemotherapy combination and chemotherapy strategy without PD-L1 test, and treatment strategy according to their PD-L1 status. RESULTS: In base case analysis, the combination strategy generated an additional 0.78 QALYs and 0.59 QALYs over chemotherapy in the United States and China respectively, resulting in an ICER of $132 392/QALY in the United States and $92 533/QALY in China. In the PD-L1 ≥1% base case, the ICERs were $77 754/QALY and $56 768/QALY respectively in the United States and China for PD-L1 test strategy. In the PD-L1 ≥50% base case, the ICERs were $44 731/QALY and $34 388/QALY respectively in the United States and China for PD-L1 test strategy. Lowering Pembro price can also partly decrease the ICERs. CONCLUSION: Compared with chemotherapy, the combination strategy is not cost-effective for the treatment of NSCLC in the American and Chinese health care system at WTP threshold of $100 000/QALY for the United States and $27 351/QALY for China. Using PD-L1 test for patient selection and price reduction could improve the cost-effective probabilities of immunotherapy for nonsquamous NSCLC.